diff --git a/src/backend/utils/adt/arrayfuncs.c b/src/backend/utils/adt/arrayfuncs.c
index 91df184..4a4ca5d 100644
*** a/src/backend/utils/adt/arrayfuncs.c
--- b/src/backend/utils/adt/arrayfuncs.c
*************** array_larger(PG_FUNCTION_ARGS)
*** 4714,4719 ****
--- 4714,4737 ----
  }
  
  Datum
+ array_larger_inv(PG_FUNCTION_ARGS)
+ {
+ 	ArrayType  *v1,
+ 			   *v2;
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function function called in non-aggregate context");
+ 
+ 	v1 = PG_GETARG_ARRAYTYPE_P(0);
+ 	v2 = PG_GETARG_ARRAYTYPE_P(1);
+ 
+ 	if (array_cmp(fcinfo) > 0)
+ 		PG_RETURN_ARRAYTYPE_P(v1);
+ 	PG_RETURN_NULL();
+ }
+ 
+ 
+ Datum
  array_smaller(PG_FUNCTION_ARGS)
  {
  	ArrayType  *v1,
*************** array_smaller(PG_FUNCTION_ARGS)
*** 4728,4733 ****
--- 4746,4767 ----
  	PG_RETURN_ARRAYTYPE_P(result);
  }
  
+ Datum
+ array_smaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	ArrayType  *v1,
+ 			   *v2;
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function function called in non-aggregate context");
+ 
+ 	v1 = PG_GETARG_ARRAYTYPE_P(0);
+ 	v2 = PG_GETARG_ARRAYTYPE_P(1);
+ 
+ 	if (array_cmp(fcinfo) < 0)
+ 		PG_RETURN_ARRAYTYPE_P(v1);
+ 	PG_RETURN_NULL();
+ }
  
  typedef struct generate_subscripts_fctx
  {
diff --git a/src/backend/utils/adt/cash.c b/src/backend/utils/adt/cash.c
index 0158758..cba17a3 100644
*** a/src/backend/utils/adt/cash.c
--- b/src/backend/utils/adt/cash.c
*************** cashlarger(PG_FUNCTION_ARGS)
*** 877,882 ****
--- 877,896 ----
  	PG_RETURN_CASH(result);
  }
  
+ Datum
+ cashlarger_inv(PG_FUNCTION_ARGS)
+ {
+ 	Cash		c1 = PG_GETARG_CASH(0);
+ 	Cash		c2 = PG_GETARG_CASH(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (c1 > c2)
+ 		PG_RETURN_CASH(c1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
  /* cashsmaller()
   * Return smaller of two cash values.
   */
*************** cashsmaller(PG_FUNCTION_ARGS)
*** 892,897 ****
--- 906,925 ----
  	PG_RETURN_CASH(result);
  }
  
+ Datum
+ cashsmaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	Cash		c1 = PG_GETARG_CASH(0);
+ 	Cash		c2 = PG_GETARG_CASH(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (c1 < c2)
+ 		PG_RETURN_CASH(c1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
  /* cash_words()
   * This converts a int4 as well but to a representation using words
   * Obviously way North American centric - sorry
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 06cc0cd..0cca0b0 100644
*** a/src/backend/utils/adt/date.c
--- b/src/backend/utils/adt/date.c
*************** date_larger(PG_FUNCTION_ARGS)
*** 396,401 ****
--- 396,415 ----
  }
  
  Datum
+ date_larger_inv(PG_FUNCTION_ARGS)
+ {
+ 	DateADT		dateVal1 = PG_GETARG_DATEADT(0);
+ 	DateADT		dateVal2 = PG_GETARG_DATEADT(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (dateVal1 > dateVal2)
+ 		PG_RETURN_DATEADT(dateVal1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
+ Datum
  date_smaller(PG_FUNCTION_ARGS)
  {
  	DateADT		dateVal1 = PG_GETARG_DATEADT(0);
*************** date_smaller(PG_FUNCTION_ARGS)
*** 404,409 ****
--- 418,437 ----
  	PG_RETURN_DATEADT((dateVal1 < dateVal2) ? dateVal1 : dateVal2);
  }
  
+ Datum
+ date_smaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	DateADT		dateVal1 = PG_GETARG_DATEADT(0);
+ 	DateADT		dateVal2 = PG_GETARG_DATEADT(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (dateVal1 < dateVal2)
+ 		PG_RETURN_DATEADT(dateVal1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
  /* Compute difference between two dates in days.
   */
  Datum
*************** time_larger(PG_FUNCTION_ARGS)
*** 1463,1468 ****
--- 1491,1510 ----
  }
  
  Datum
+ time_larger_inv(PG_FUNCTION_ARGS)
+ {
+ 	TimeADT		time1 = PG_GETARG_TIMEADT(0);
+ 	TimeADT		time2 = PG_GETARG_TIMEADT(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (time1 > time2)
+ 		PG_RETURN_TIMEADT(time1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
+ Datum
  time_smaller(PG_FUNCTION_ARGS)
  {
  	TimeADT		time1 = PG_GETARG_TIMEADT(0);
*************** time_smaller(PG_FUNCTION_ARGS)
*** 1471,1476 ****
--- 1513,1532 ----
  	PG_RETURN_TIMEADT((time1 < time2) ? time1 : time2);
  }
  
+ Datum
+ time_smaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	TimeADT		time1 = PG_GETARG_TIMEADT(0);
+ 	TimeADT		time2 = PG_GETARG_TIMEADT(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (time1 < time2)
+ 		PG_RETURN_TIMEADT(time1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
  /* overlaps_time() --- implements the SQL OVERLAPS operator.
   *
   * Algorithm is per SQL spec.  This is much harder than you'd think
*************** timetz_larger(PG_FUNCTION_ARGS)
*** 2262,2267 ****
--- 2318,2337 ----
  }
  
  Datum
+ timetz_larger_inv(PG_FUNCTION_ARGS)
+ {
+ 	TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
+ 	TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (timetz_cmp_internal(time1, time2) > 0)
+ 		PG_RETURN_TIMETZADT_P(time1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
+ Datum
  timetz_smaller(PG_FUNCTION_ARGS)
  {
  	TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
*************** timetz_smaller(PG_FUNCTION_ARGS)
*** 2275,2280 ****
--- 2345,2364 ----
  	PG_RETURN_TIMETZADT_P(result);
  }
  
+ Datum
+ timetz_smaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
+ 	TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (timetz_cmp_internal(time1, time2) < 0)
+ 		PG_RETURN_TIMETZADT_P(time1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
  /* timetz_pl_interval()
   * Add interval to timetz.
   */
diff --git a/src/backend/utils/adt/enum.c b/src/backend/utils/adt/enum.c
index 83c3878..32035e0 100644
*** a/src/backend/utils/adt/enum.c
--- b/src/backend/utils/adt/enum.c
*************** enum_smaller(PG_FUNCTION_ARGS)
*** 273,278 ****
--- 273,292 ----
  }
  
  Datum
+ enum_smaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	Oid			a = PG_GETARG_OID(0);
+ 	Oid			b = PG_GETARG_OID(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (enum_cmp_internal(a, b, fcinfo) < 0)
+ 		PG_RETURN_OID(a);
+ 	PG_RETURN_NULL();
+ }
+ 
+ Datum
  enum_larger(PG_FUNCTION_ARGS)
  {
  	Oid			a = PG_GETARG_OID(0);
*************** enum_larger(PG_FUNCTION_ARGS)
*** 282,287 ****
--- 296,315 ----
  }
  
  Datum
+ enum_larger_inv(PG_FUNCTION_ARGS)
+ {
+ 	Oid			a = PG_GETARG_OID(0);
+ 	Oid			b = PG_GETARG_OID(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (enum_cmp_internal(a, b, fcinfo) > 0)
+ 		PG_RETURN_OID(a);
+ 	PG_RETURN_NULL();
+ }
+ 
+ Datum
  enum_cmp(PG_FUNCTION_ARGS)
  {
  	Oid			a = PG_GETARG_OID(0);
diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c
index 774267e..04f89b0 100644
*** a/src/backend/utils/adt/float.c
--- b/src/backend/utils/adt/float.c
*************** float4larger(PG_FUNCTION_ARGS)
*** 637,642 ****
--- 637,658 ----
  }
  
  Datum
+ float4larger_inv(PG_FUNCTION_ARGS)
+ {
+ 	float4		arg1 = PG_GETARG_FLOAT4(0);
+ 	float4		arg2 = PG_GETARG_FLOAT4(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (isnan(arg1) || isnan(arg2))
+ 		PG_RETURN_NULL();
+ 	else if (float4_cmp_internal(arg1, arg2) > 0)
+ 		PG_RETURN_FLOAT4(arg1);
+ 	PG_RETURN_NULL();
+ }
+ 
+ Datum
  float4smaller(PG_FUNCTION_ARGS)
  {
  	float4		arg1 = PG_GETARG_FLOAT4(0);
*************** float4smaller(PG_FUNCTION_ARGS)
*** 650,655 ****
--- 666,687 ----
  	PG_RETURN_FLOAT4(result);
  }
  
+ Datum
+ float4smaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	float4		arg1 = PG_GETARG_FLOAT4(0);
+ 	float4		arg2 = PG_GETARG_FLOAT4(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (isnan(arg1) || isnan(arg2))
+ 		PG_RETURN_NULL();
+ 	else if (float4_cmp_internal(arg1, arg2) < 0)
+ 		PG_RETURN_FLOAT4(arg1);
+ 	PG_RETURN_NULL();
+ }
+ 
  /*
   *		======================
   *		FLOAT8 BASE OPERATIONS
*************** float8larger(PG_FUNCTION_ARGS)
*** 704,709 ****
--- 736,757 ----
  }
  
  Datum
+ float8larger_inv(PG_FUNCTION_ARGS)
+ {
+ 	float8		arg1 = PG_GETARG_FLOAT8(0);
+ 	float8		arg2 = PG_GETARG_FLOAT8(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (isnan(arg1) || isnan(arg2))
+ 		PG_RETURN_NULL();
+ 	else if (float8_cmp_internal(arg1, arg2) > 0)
+ 		PG_RETURN_FLOAT8(arg1);
+ 	PG_RETURN_NULL();
+ }
+ 
+ Datum
  float8smaller(PG_FUNCTION_ARGS)
  {
  	float8		arg1 = PG_GETARG_FLOAT8(0);
*************** float8smaller(PG_FUNCTION_ARGS)
*** 717,722 ****
--- 765,785 ----
  	PG_RETURN_FLOAT8(result);
  }
  
+ Datum
+ float8smaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	float8		arg1 = PG_GETARG_FLOAT8(0);
+ 	float8		arg2 = PG_GETARG_FLOAT8(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (isnan(arg1) || isnan(arg2))
+ 		PG_RETURN_NULL();
+ 	else if (float8_cmp_internal(arg1, arg2) < 0)
+ 		PG_RETURN_FLOAT8(arg1);
+ 	PG_RETURN_NULL();
+ }
  
  /*
   *		====================
diff --git a/src/backend/utils/adt/int.c b/src/backend/utils/adt/int.c
index 669355e..fe9d736 100644
*** a/src/backend/utils/adt/int.c
--- b/src/backend/utils/adt/int.c
*************** int2larger(PG_FUNCTION_ARGS)
*** 1185,1190 ****
--- 1185,1204 ----
  }
  
  Datum
+ int2larger_inv(PG_FUNCTION_ARGS)
+ {
+ 	int16		arg1 = PG_GETARG_INT16(0);
+ 	int16		arg2 = PG_GETARG_INT16(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (arg1 > arg2)
+ 		PG_RETURN_INT16(arg1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
+ Datum
  int2smaller(PG_FUNCTION_ARGS)
  {
  	int16		arg1 = PG_GETARG_INT16(0);
*************** int2smaller(PG_FUNCTION_ARGS)
*** 1194,1199 ****
--- 1208,1227 ----
  }
  
  Datum
+ int2smaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	int16		arg1 = PG_GETARG_INT16(0);
+ 	int16		arg2 = PG_GETARG_INT16(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (arg1 < arg2)
+ 		PG_RETURN_INT16(arg1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
+ Datum
  int4larger(PG_FUNCTION_ARGS)
  {
  	int32		arg1 = PG_GETARG_INT32(0);
*************** int4larger(PG_FUNCTION_ARGS)
*** 1203,1208 ****
--- 1231,1250 ----
  }
  
  Datum
+ int4larger_inv(PG_FUNCTION_ARGS)
+ {
+ 	int32		arg1 = PG_GETARG_INT32(0);
+ 	int32		arg2 = PG_GETARG_INT32(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (arg1 > arg2)
+ 		PG_RETURN_INT32(arg1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
+ Datum
  int4smaller(PG_FUNCTION_ARGS)
  {
  	int32		arg1 = PG_GETARG_INT32(0);
*************** int4smaller(PG_FUNCTION_ARGS)
*** 1211,1216 ****
--- 1253,1272 ----
  	PG_RETURN_INT32((arg1 < arg2) ? arg1 : arg2);
  }
  
+ Datum
+ int4smaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	int32		arg1 = PG_GETARG_INT32(0);
+ 	int32		arg2 = PG_GETARG_INT32(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (arg1 < arg2)
+ 		PG_RETURN_INT32(arg1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
  /*
   * Bit-pushing operators
   *
diff --git a/src/backend/utils/adt/int8.c b/src/backend/utils/adt/int8.c
index 5e1be90..820be68 100644
*** a/src/backend/utils/adt/int8.c
--- b/src/backend/utils/adt/int8.c
*************** int8larger(PG_FUNCTION_ARGS)
*** 752,757 ****
--- 752,771 ----
  }
  
  Datum
+ int8larger_inv(PG_FUNCTION_ARGS)
+ {
+ 	int64		arg1 = PG_GETARG_INT64(0);
+ 	int64		arg2 = PG_GETARG_INT64(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (arg1 > arg2)
+ 		PG_RETURN_INT64(arg1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
+ Datum
  int8smaller(PG_FUNCTION_ARGS)
  {
  	int64		arg1 = PG_GETARG_INT64(0);
*************** int8smaller(PG_FUNCTION_ARGS)
*** 764,769 ****
--- 778,797 ----
  }
  
  Datum
+ int8smaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	int64		arg1 = PG_GETARG_INT64(0);
+ 	int64		arg2 = PG_GETARG_INT64(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (arg1 < arg2)
+ 		PG_RETURN_INT64(arg1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
+ Datum
  int84pl(PG_FUNCTION_ARGS)
  {
  	int64		arg1 = PG_GETARG_INT64(0);
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 64eb0f8..c9500bf 100644
*** a/src/backend/utils/adt/numeric.c
--- b/src/backend/utils/adt/numeric.c
*************** numeric_smaller(PG_FUNCTION_ARGS)
*** 1872,1877 ****
--- 1872,1892 ----
  		PG_RETURN_NUMERIC(num2);
  }
  
+ Datum
+ numeric_smaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	Numeric		num1 = PG_GETARG_NUMERIC(0);
+ 	Numeric		num2 = PG_GETARG_NUMERIC(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (NUMERIC_IS_NAN(num1) || NUMERIC_IS_NAN(num2))
+ 		PG_RETURN_NULL();
+ 	else if (cmp_numerics(num1, num2) < 0)
+ 		PG_RETURN_NUMERIC(num1);
+ 	PG_RETURN_NULL();
+ }
  
  /*
   * numeric_larger() -
*************** numeric_larger(PG_FUNCTION_ARGS)
*** 1894,1899 ****
--- 1909,1930 ----
  		PG_RETURN_NUMERIC(num2);
  }
  
+ Datum
+ numeric_larger_inv(PG_FUNCTION_ARGS)
+ {
+ 	Numeric		num1 = PG_GETARG_NUMERIC(0);
+ 	Numeric		num2 = PG_GETARG_NUMERIC(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (NUMERIC_IS_NAN(num1) || NUMERIC_IS_NAN(num2))
+ 		PG_RETURN_NULL();
+ 	else if (cmp_numerics(num1, num2) > 0)
+ 		PG_RETURN_NUMERIC(num1);
+ 	PG_RETURN_NULL();
+ }
+ 
  
  /* ----------------------------------------------------------------------
   *
diff --git a/src/backend/utils/adt/oid.c b/src/backend/utils/adt/oid.c
index 8945ef4..745449a 100644
*** a/src/backend/utils/adt/oid.c
--- b/src/backend/utils/adt/oid.c
*************** oidlarger(PG_FUNCTION_ARGS)
*** 397,402 ****
--- 397,416 ----
  }
  
  Datum
+ oidlarger_inv(PG_FUNCTION_ARGS)
+ {
+ 	Oid			arg1 = PG_GETARG_OID(0);
+ 	Oid			arg2 = PG_GETARG_OID(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (arg1 > arg2)
+ 		PG_RETURN_OID(arg1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
+ Datum
  oidsmaller(PG_FUNCTION_ARGS)
  {
  	Oid			arg1 = PG_GETARG_OID(0);
*************** oidsmaller(PG_FUNCTION_ARGS)
*** 406,411 ****
--- 420,439 ----
  }
  
  Datum
+ oidsmaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	Oid			arg1 = PG_GETARG_OID(0);
+ 	Oid			arg2 = PG_GETARG_OID(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (arg1 < arg2)
+ 		PG_RETURN_OID(arg1);
+ 	PG_RETURN_NULL(); /* Unable to perform inverse transition */
+ }
+ 
+ Datum
  oidvectoreq(PG_FUNCTION_ARGS)
  {
  	int32		cmp = DatumGetInt32(btoidvectorcmp(fcinfo));
diff --git a/src/backend/utils/adt/tid.c b/src/backend/utils/adt/tid.c
index 6e2bbdc..57fcf80 100644
*** a/src/backend/utils/adt/tid.c
--- b/src/backend/utils/adt/tid.c
*************** tidlarger(PG_FUNCTION_ARGS)
*** 237,242 ****
--- 237,256 ----
  }
  
  Datum
+ tidlarger_inv(PG_FUNCTION_ARGS)
+ {
+ 	ItemPointer arg1 = PG_GETARG_ITEMPOINTER(0);
+ 	ItemPointer arg2 = PG_GETARG_ITEMPOINTER(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (ItemPointerCompare(arg1, arg2) > 0)
+ 		PG_RETURN_ITEMPOINTER(arg1);
+ 	PG_RETURN_NULL();
+ }
+ 
+ Datum
  tidsmaller(PG_FUNCTION_ARGS)
  {
  	ItemPointer arg1 = PG_GETARG_ITEMPOINTER(0);
*************** tidsmaller(PG_FUNCTION_ARGS)
*** 245,250 ****
--- 259,277 ----
  	PG_RETURN_ITEMPOINTER(ItemPointerCompare(arg1, arg2) <= 0 ? arg1 : arg2);
  }
  
+ Datum
+ tidsmaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	ItemPointer arg1 = PG_GETARG_ITEMPOINTER(0);
+ 	ItemPointer arg2 = PG_GETARG_ITEMPOINTER(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (ItemPointerCompare(arg1, arg2) < 0)
+ 		PG_RETURN_ITEMPOINTER(arg1);
+ 	PG_RETURN_NULL();
+ }
  
  /*
   *	Functions to get latest tid of a specified tuple.
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index ce30bb6..e611983 100644
*** a/src/backend/utils/adt/timestamp.c
--- b/src/backend/utils/adt/timestamp.c
*************** timestamp_smaller(PG_FUNCTION_ARGS)
*** 2682,2687 ****
--- 2682,2701 ----
  }
  
  Datum
+ timestamp_smaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	Timestamp	dt1 = PG_GETARG_TIMESTAMP(0);
+ 	Timestamp	dt2 = PG_GETARG_TIMESTAMP(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (timestamp_cmp_internal(dt1, dt2) < 0)
+ 		PG_RETURN_TIMESTAMP(dt1);
+ 	PG_RETURN_NULL();
+ }
+ 
+ Datum
  timestamp_larger(PG_FUNCTION_ARGS)
  {
  	Timestamp	dt1 = PG_GETARG_TIMESTAMP(0);
*************** timestamp_larger(PG_FUNCTION_ARGS)
*** 2695,2700 ****
--- 2709,2727 ----
  	PG_RETURN_TIMESTAMP(result);
  }
  
+ Datum
+ timestamp_larger_inv(PG_FUNCTION_ARGS)
+ {
+ 	Timestamp	dt1 = PG_GETARG_TIMESTAMP(0);
+ 	Timestamp	dt2 = PG_GETARG_TIMESTAMP(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (timestamp_cmp_internal(dt1, dt2) > 0)
+ 		PG_RETURN_TIMESTAMP(dt1);
+ 	PG_RETURN_NULL();
+ }
  
  Datum
  timestamp_mi(PG_FUNCTION_ARGS)
*************** interval_smaller(PG_FUNCTION_ARGS)
*** 3151,3156 ****
--- 3178,3197 ----
  }
  
  Datum
+ interval_smaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	Interval   *interval1 = PG_GETARG_INTERVAL_P(0);
+ 	Interval   *interval2 = PG_GETARG_INTERVAL_P(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (interval_cmp_internal(interval1, interval2) < 0)
+ 		PG_RETURN_INTERVAL_P(interval1);
+ 	PG_RETURN_NULL();
+ }
+ 
+ Datum
  interval_larger(PG_FUNCTION_ARGS)
  {
  	Interval   *interval1 = PG_GETARG_INTERVAL_P(0);
*************** interval_larger(PG_FUNCTION_ARGS)
*** 3165,3170 ****
--- 3206,3225 ----
  }
  
  Datum
+ interval_larger_inv(PG_FUNCTION_ARGS)
+ {
+ 	Interval   *interval1 = PG_GETARG_INTERVAL_P(0);
+ 	Interval   *interval2 = PG_GETARG_INTERVAL_P(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (interval_cmp_internal(interval1, interval2) > 0)
+ 		PG_RETURN_INTERVAL_P(interval1);
+ 	PG_RETURN_NULL();
+ }
+ 
+ Datum
  interval_pl(PG_FUNCTION_ARGS)
  {
  	Interval   *span1 = PG_GETARG_INTERVAL_P(0);
diff --git a/src/backend/utils/adt/varchar.c b/src/backend/utils/adt/varchar.c
index 502ca44..536ca66 100644
*** a/src/backend/utils/adt/varchar.c
--- b/src/backend/utils/adt/varchar.c
*************** bpchar_larger(PG_FUNCTION_ARGS)
*** 877,882 ****
--- 877,905 ----
  }
  
  Datum
+ bpchar_larger_inv(PG_FUNCTION_ARGS)
+ {
+ 	BpChar	   *arg1 = PG_GETARG_BPCHAR_PP(0);
+ 	BpChar	   *arg2 = PG_GETARG_BPCHAR_PP(1);
+ 	int			len1,
+ 				len2;
+ 	int			cmp;
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	len1 = bcTruelen(arg1);
+ 	len2 = bcTruelen(arg2);
+ 
+ 	cmp = varstr_cmp(VARDATA_ANY(arg1), len1, VARDATA_ANY(arg2), len2,
+ 		PG_GET_COLLATION());
+ 
+ 	if (cmp > 0)
+ 		PG_RETURN_BPCHAR_P(arg1);
+ 	PG_RETURN_NULL();
+ }
+ 
+ Datum
  bpchar_smaller(PG_FUNCTION_ARGS)
  {
  	BpChar	   *arg1 = PG_GETARG_BPCHAR_PP(0);
*************** bpchar_smaller(PG_FUNCTION_ARGS)
*** 894,899 ****
--- 917,945 ----
  	PG_RETURN_BPCHAR_P((cmp <= 0) ? arg1 : arg2);
  }
  
+ Datum
+ bpchar_smaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	BpChar	   *arg1 = PG_GETARG_BPCHAR_PP(0);
+ 	BpChar	   *arg2 = PG_GETARG_BPCHAR_PP(1);
+ 	int			len1,
+ 				len2;
+ 	int			cmp;
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	len1 = bcTruelen(arg1);
+ 	len2 = bcTruelen(arg2);
+ 
+ 	cmp = varstr_cmp(VARDATA_ANY(arg1), len1, VARDATA_ANY(arg2), len2,
+ 		PG_GET_COLLATION());
+ 
+ 	if (cmp < 0)
+ 		PG_RETURN_BPCHAR_P(arg1);
+ 	PG_RETURN_NULL();
+ }
+ 
  
  /*
   * bpchar needs a specialized hash function because we want to ignore
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index cb07a06..821cded 100644
*** a/src/backend/utils/adt/varlena.c
--- b/src/backend/utils/adt/varlena.c
*************** text_larger(PG_FUNCTION_ARGS)
*** 1697,1702 ****
--- 1697,1716 ----
  }
  
  Datum
+ text_larger_inv(PG_FUNCTION_ARGS)
+ {
+ 	text	   *arg1 = PG_GETARG_TEXT_PP(0);
+ 	text	   *arg2 = PG_GETARG_TEXT_PP(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (text_cmp(arg1, arg2, PG_GET_COLLATION()) > 0)
+ 		PG_RETURN_TEXT_P(arg1);
+ 	PG_RETURN_NULL();
+ }
+ 
+ Datum
  text_smaller(PG_FUNCTION_ARGS)
  {
  	text	   *arg1 = PG_GETARG_TEXT_PP(0);
*************** text_smaller(PG_FUNCTION_ARGS)
*** 1708,1713 ****
--- 1722,1740 ----
  	PG_RETURN_TEXT_P(result);
  }
  
+ Datum
+ text_smaller_inv(PG_FUNCTION_ARGS)
+ {
+ 	text	   *arg1 = PG_GETARG_TEXT_PP(0);
+ 	text	   *arg2 = PG_GETARG_TEXT_PP(1);
+ 
+ 	if (!AggCheckCallContext(fcinfo, NULL))
+ 		elog(ERROR, "aggregate inverse transition function called in non-aggregate context");
+ 
+ 	if (text_cmp(arg1, arg2, PG_GET_COLLATION()) < 0)
+ 		PG_RETURN_TEXT_P(arg1);
+ 	PG_RETURN_NULL();
+ }
  
  /*
   * The following operators support character-by-character comparison
diff --git a/src/include/catalog/pg_aggregate.h b/src/include/catalog/pg_aggregate.h
index 3412661..f1a602d 100644
*** a/src/include/catalog/pg_aggregate.h
--- b/src/include/catalog/pg_aggregate.h
*************** DATA(insert ( 2113	n 0 interval_pl		-	-	
*** 122,169 ****
  DATA(insert ( 2114	n 0 numeric_avg_accum	-	numeric_sum 0	2281	128 _null_ ));
  
  /* max */
! DATA(insert ( 2115	n 0 int8larger		-	-				413		20		0	_null_ ));
! DATA(insert ( 2116	n 0 int4larger		-	-				521		23		0	_null_ ));
! DATA(insert ( 2117	n 0 int2larger		-	-				520		21		0	_null_ ));
! DATA(insert ( 2118	n 0 oidlarger		-	-				610		26		0	_null_ ));
! DATA(insert ( 2119	n 0 float4larger	-	-				623		700		0	_null_ ));
! DATA(insert ( 2120	n 0 float8larger	-	-				674		701		0	_null_ ));
! DATA(insert ( 2121	n 0 int4larger		-	-				563		702		0	_null_ ));
! DATA(insert ( 2122	n 0 date_larger		-	-				1097	1082	0	_null_ ));
! DATA(insert ( 2123	n 0 time_larger		-	-				1112	1083	0	_null_ ));
! DATA(insert ( 2124	n 0 timetz_larger	-	-				1554	1266	0	_null_ ));
! DATA(insert ( 2125	n 0 cashlarger		-	-				903		790		0	_null_ ));
! DATA(insert ( 2126	n 0 timestamp_larger	-	-			2064	1114	0	_null_ ));
! DATA(insert ( 2127	n 0 timestamptz_larger	-	-			1324	1184	0	_null_ ));
! DATA(insert ( 2128	n 0 interval_larger -	-				1334	1186	0	_null_ ));
! DATA(insert ( 2129	n 0 text_larger		-	-				666		25		0	_null_ ));
! DATA(insert ( 2130	n 0 numeric_larger	-	-				1756	1700	0	_null_ ));
! DATA(insert ( 2050	n 0 array_larger	-	-				1073	2277	0	_null_ ));
! DATA(insert ( 2244	n 0 bpchar_larger	-	-				1060	1042	0	_null_ ));
! DATA(insert ( 2797	n 0 tidlarger		-	-				2800	27		0	_null_ ));
! DATA(insert ( 3526	n 0 enum_larger		-	-				3519	3500	0	_null_ ));
  
  /* min */
! DATA(insert ( 2131	n 0 int8smaller		-	-				412		20		0	_null_ ));
! DATA(insert ( 2132	n 0 int4smaller		-	-				97		23		0	_null_ ));
! DATA(insert ( 2133	n 0 int2smaller		-	-				95		21		0	_null_ ));
! DATA(insert ( 2134	n 0 oidsmaller		-	-				609		26		0	_null_ ));
! DATA(insert ( 2135	n 0 float4smaller	-	-				622		700		0	_null_ ));
! DATA(insert ( 2136	n 0 float8smaller	-	-				672		701		0	_null_ ));
! DATA(insert ( 2137	n 0 int4smaller		-	-				562		702		0	_null_ ));
! DATA(insert ( 2138	n 0 date_smaller	-	-				1095	1082	0	_null_ ));
! DATA(insert ( 2139	n 0 time_smaller	-	-				1110	1083	0	_null_ ));
! DATA(insert ( 2140	n 0 timetz_smaller	-	-				1552	1266	0	_null_ ));
! DATA(insert ( 2141	n 0 cashsmaller		-	-				902		790		0	_null_ ));
! DATA(insert ( 2142	n 0 timestamp_smaller	-	-			2062	1114	0	_null_ ));
! DATA(insert ( 2143	n 0 timestamptz_smaller -	-			1322	1184	0	_null_ ));
! DATA(insert ( 2144	n 0 interval_smaller	-	-			1332	1186	0	_null_ ));
! DATA(insert ( 2145	n 0 text_smaller	-	-				664		25		0	_null_ ));
! DATA(insert ( 2146	n 0 numeric_smaller -	-				1754	1700	0	_null_ ));
! DATA(insert ( 2051	n 0 array_smaller	-	-				1072	2277	0	_null_ ));
! DATA(insert ( 2245	n 0 bpchar_smaller	-	-				1058	1042	0	_null_ ));
! DATA(insert ( 2798	n 0 tidsmaller		-	-				2799	27		0	_null_ ));
! DATA(insert ( 3527	n 0 enum_smaller	-	-				3518	3500	0	_null_ ));
  
  /* count */
  DATA(insert ( 2147	n 0 int8inc_any		-	-				0		20		0	"0" ));
--- 122,169 ----
  DATA(insert ( 2114	n 0 numeric_avg_accum	-	numeric_sum 0	2281	128 _null_ ));
  
  /* max */
! DATA(insert ( 2115	n 0 int8larger			int8larger_inv			-		413		20		0	_null_ ));
! DATA(insert ( 2116	n 0 int4larger			int4larger_inv			-		521		23		0	_null_ ));
! DATA(insert ( 2117	n 0 int2larger			int2larger_inv			-		520		21		0	_null_ ));
! DATA(insert ( 2118	n 0 oidlarger			oidlarger_inv			-		610		26		0	_null_ ));
! DATA(insert ( 2119	n 0 float4larger		float4larger_inv		-		623		700		0	_null_ ));
! DATA(insert ( 2120	n 0 float8larger		float8larger_inv		-		674		701		0	_null_ ));
! DATA(insert ( 2121	n 0 int4larger			int4larger_inv			-		563		702		0	_null_ ));
! DATA(insert ( 2122	n 0 date_larger			date_larger_inv			-		1097	1082	0	_null_ ));
! DATA(insert ( 2123	n 0 time_larger			time_larger_inv			-		1112	1083	0	_null_ ));
! DATA(insert ( 2124	n 0 timetz_larger		timetz_larger_inv		-		1554	1266	0	_null_ ));
! DATA(insert ( 2125	n 0 cashlarger			cashlarger_inv			-		903		790		0	_null_ ));
! DATA(insert ( 2126	n 0 timestamp_larger	timestamp_larger_inv	-		2064	1114	0	_null_ ));
! DATA(insert ( 2127	n 0 timestamptz_larger	timestamptz_larger_inv	-		1324	1184	0	_null_ ));
! DATA(insert ( 2128	n 0 interval_larger		interval_larger_inv		-		1334	1186	0	_null_ ));
! DATA(insert ( 2129	n 0 text_larger			text_larger_inv			-		666		25		0	_null_ ));
! DATA(insert ( 2130	n 0 numeric_larger		numeric_larger_inv		-		1756	1700	0	_null_ ));
! DATA(insert ( 2050	n 0 array_larger		array_larger_inv		-		1073	2277	0	_null_ ));
! DATA(insert ( 2244	n 0 bpchar_larger		bpchar_larger_inv		-		1060	1042	0	_null_ ));
! DATA(insert ( 2797	n 0 tidlarger			tidlarger_inv			-		2800	27		0	_null_ ));
! DATA(insert ( 3526	n 0 enum_larger			enum_larger_inv			-		3519	3500	0	_null_ ));
  
  /* min */
! DATA(insert ( 2131	n 0 int8smaller			int8smaller_inv			-		412		20		0	_null_ ));
! DATA(insert ( 2132	n 0 int4smaller			int4smaller_inv			-		97		23		0	_null_ ));
! DATA(insert ( 2133	n 0 int2smaller			int2smaller_inv			-		95		21		0	_null_ ));
! DATA(insert ( 2134	n 0 oidsmaller			oidsmaller_inv			-		609		26		0	_null_ ));
! DATA(insert ( 2135	n 0 float4smaller		float4smaller_inv		-		622		700		0	_null_ ));
! DATA(insert ( 2136	n 0 float8smaller		float8smaller_inv		-		672		701		0	_null_ ));
! DATA(insert ( 2137	n 0 int4smaller			int4smaller_inv			-		562		702		0	_null_ ));
! DATA(insert ( 2138	n 0 date_smaller		date_smaller_inv		-		1095	1082	0	_null_ ));
! DATA(insert ( 2139	n 0 time_smaller		time_smaller_inv		-		1110	1083	0	_null_ ));
! DATA(insert ( 2140	n 0 timetz_smaller		timetz_smaller_inv		-		1552	1266	0	_null_ ));
! DATA(insert ( 2141	n 0 cashsmaller			cashsmaller_inv			-		902		790		0	_null_ ));
! DATA(insert ( 2142	n 0 timestamp_smaller	timestamp_smaller_inv	-		2062	1114	0	_null_ ));
! DATA(insert ( 2143	n 0 timestamptz_smaller timestamptz_smaller_inv	-		1322	1184	0	_null_ ));
! DATA(insert ( 2144	n 0 interval_smaller	interval_smaller_inv	-		1332	1186	0	_null_ ));
! DATA(insert ( 2145	n 0 text_smaller		text_smaller_inv		-		664		25		0	_null_ ));
! DATA(insert ( 2146	n 0 numeric_smaller		numeric_smaller_inv		-		1754	1700	0	_null_ ));
! DATA(insert ( 2051	n 0 array_smaller		array_smaller_inv		-		1072	2277	0	_null_ ));
! DATA(insert ( 2245	n 0 bpchar_smaller		bpchar_smaller_inv		-		1058	1042	0	_null_ ));
! DATA(insert ( 2798	n 0 tidsmaller			tidsmaller_inv			-		2799	27		0	_null_ ));
! DATA(insert ( 3527	n 0 enum_smaller		enum_smaller_inv		-		3518	3500	0	_null_ ));
  
  /* count */
  DATA(insert ( 2147	n 0 int8inc_any		-	-				0		20		0	"0" ));
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 334e6b8..42dcb27 100644
*** a/src/include/catalog/pg_proc.h
--- b/src/include/catalog/pg_proc.h
*************** DESCR("larger of two");
*** 367,372 ****
--- 367,377 ----
  DATA(insert OID = 211 (  float4smaller	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 700 "700 700" _null_ _null_ _null_ _null_	float4smaller _null_ _null_ _null_ ));
  DESCR("smaller of two");
  
+ DATA(insert OID = 3567 (  float4larger_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 700 "700 700" _null_ _null_ _null_ _null_	float4larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 3568 (  float4smaller_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 700 "700 700" _null_ _null_ _null_ _null_	float4smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ 
  DATA(insert OID = 212 (  int4um			   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 23 "23" _null_ _null_ _null_ _null_ int4um _null_ _null_ _null_ ));
  DATA(insert OID = 213 (  int2um			   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 21 "21" _null_ _null_ _null_ _null_ int2um _null_ _null_ _null_ ));
  
*************** DATA(insert OID = 223 (  float8larger	  
*** 386,391 ****
--- 391,400 ----
  DESCR("larger of two");
  DATA(insert OID = 224 (  float8smaller	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 701 "701 701" _null_ _null_ _null_ _null_	float8smaller _null_ _null_ _null_ ));
  DESCR("smaller of two");
+ DATA(insert OID = 3569 (  float8larger_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 701 "701 701" _null_ _null_ _null_ _null_	float8larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 3570 (  float8smaller_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 701 "701 701" _null_ _null_ _null_ _null_	float8smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
  
  DATA(insert OID = 225 (  lseg_center	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 600 "601" _null_ _null_ _null_ _null_	lseg_center _null_ _null_ _null_ ));
  DATA(insert OID = 226 (  path_center	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 600 "602" _null_ _null_ _null_ _null_	path_center _null_ _null_ _null_ ));
*************** DATA(insert OID = 458 (  text_larger	   
*** 711,716 ****
--- 720,729 ----
  DESCR("larger of two");
  DATA(insert OID = 459 (  text_smaller	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 25 "25 25" _null_ _null_ _null_ _null_ text_smaller _null_ _null_ _null_ ));
  DESCR("smaller of two");
+ DATA(insert OID = 3571 (  text_larger_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 25 "25 25" _null_ _null_ _null_ _null_ text_larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 3572 (  text_smaller_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 25 "25 25" _null_ _null_ _null_ _null_ text_smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
  
  DATA(insert OID = 460 (  int8in			   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 20 "2275" _null_ _null_ _null_ _null_ int8in _null_ _null_ _null_ ));
  DESCR("I/O");
*************** DATA(insert OID = 515 (  array_larger	  
*** 859,864 ****
--- 872,881 ----
  DESCR("larger of two");
  DATA(insert OID = 516 (  array_smaller	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 2277 "2277 2277" _null_ _null_ _null_ _null_ array_smaller _null_ _null_ _null_ ));
  DESCR("smaller of two");
+ DATA(insert OID = 3573 (  array_larger_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 2277 "2277 2277" _null_ _null_ _null_ _null_ array_larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 3574 (  array_smaller_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 2277 "2277 2277" _null_ _null_ _null_ _null_ array_smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
  DATA(insert OID = 1191 (  generate_subscripts PGNSP PGUID 12 1 1000 0 0 f f f f t t i 3 0 23 "2277 23 16" _null_ _null_ _null_ _null_ generate_subscripts _null_ _null_ _null_ ));
  DESCR("array subscripts generator");
  DATA(insert OID = 1192 (  generate_subscripts PGNSP PGUID 12 1 1000 0 0 f f f f t t i 2 0 23 "2277 23" _null_ _null_ _null_ _null_ generate_subscripts_nodir _null_ _null_ _null_ ));
*************** DESCR("larger of two");
*** 913,918 ****
--- 930,945 ----
  DATA(insert OID = 771 (  int2smaller	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 21 "21 21" _null_ _null_ _null_ _null_ int2smaller _null_ _null_ _null_ ));
  DESCR("smaller of two");
  
+ DATA(insert OID = 3575 (  int4larger_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 23 "23 23" _null_ _null_ _null_ _null_ int4larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 3576 (  int4smaller_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 23 "23 23" _null_ _null_ _null_ _null_ int4smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 3577 (  int2larger_inv		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 21 "21 21" _null_ _null_ _null_ _null_ int2larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 3578 (  int2smaller_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 21 "21 21" _null_ _null_ _null_ _null_ int2smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ 
+ 
  DATA(insert OID = 774 (  gistgettuple	   PGNSP PGUID 12 1 0 0 0 f f f f t f v 2 0 16 "2281 2281" _null_ _null_ _null_ _null_	gistgettuple _null_ _null_ _null_ ));
  DESCR("gist(internal)");
  DATA(insert OID = 638 (  gistgetbitmap	   PGNSP PGUID 12 1 0 0 0 f f f f t f v 2 0 20 "2281 2281" _null_ _null_ _null_ _null_	gistgetbitmap _null_ _null_ _null_ ));
*************** DATA(insert OID =  898 (  cashlarger	   
*** 1003,1008 ****
--- 1030,1039 ----
  DESCR("larger of two");
  DATA(insert OID =  899 (  cashsmaller	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 790 "790 790" _null_ _null_ _null_ _null_	cashsmaller _null_ _null_ _null_ ));
  DESCR("smaller of two");
+ DATA(insert OID =  3579 (  cashlarger_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 790 "790 790" _null_ _null_ _null_ _null_	cashlarger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID =  3580 (  cashsmaller_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 790 "790 790" _null_ _null_ _null_ _null_	cashsmaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
  DATA(insert OID =  919 (  flt8_mul_cash    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 790 "701 790" _null_ _null_ _null_ _null_	flt8_mul_cash _null_ _null_ _null_ ));
  DATA(insert OID =  935 (  cash_words	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 25 "790" _null_ _null_ _null_ _null_	cash_words _null_ _null_ _null_ ));
  DESCR("output money amount as words");
*************** DATA(insert OID = 1063 (  bpchar_larger 
*** 1157,1162 ****
--- 1188,1197 ----
  DESCR("larger of two");
  DATA(insert OID = 1064 (  bpchar_smaller   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1042 "1042 1042" _null_ _null_ _null_ _null_ bpchar_smaller _null_ _null_ _null_ ));
  DESCR("smaller of two");
+ DATA(insert OID = 3581 (  bpchar_larger_inv    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1042 "1042 1042" _null_ _null_ _null_ _null_ bpchar_larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 3582 (  bpchar_smaller_inv   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1042 "1042 1042" _null_ _null_ _null_ _null_ bpchar_smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
  DATA(insert OID = 1078 (  bpcharcmp		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 23 "1042 1042" _null_ _null_ _null_ _null_ bpcharcmp _null_ _null_ _null_ ));
  DESCR("less-equal-greater");
  DATA(insert OID = 1080 (  hashbpchar	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 23 "1042" _null_ _null_ _null_ _null_	hashbpchar _null_ _null_ _null_ ));
*************** DATA(insert OID = 1138 (  date_larger	  
*** 1191,1196 ****
--- 1226,1235 ----
  DESCR("larger of two");
  DATA(insert OID = 1139 (  date_smaller	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1082 "1082 1082" _null_ _null_ _null_ _null_ date_smaller _null_ _null_ _null_ ));
  DESCR("smaller of two");
+ DATA(insert OID = 3583 (  date_larger_inv  PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1082 "1082 1082" _null_ _null_ _null_ _null_ date_larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 3584 (  date_smaller_inv PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1082 "1082 1082" _null_ _null_ _null_ _null_ date_smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
  DATA(insert OID = 1140 (  date_mi		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 23 "1082 1082" _null_ _null_ _null_ _null_ date_mi _null_ _null_ _null_ ));
  DATA(insert OID = 1141 (  date_pli		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1082 "1082 23" _null_ _null_ _null_ _null_ date_pli _null_ _null_ _null_ ));
  DATA(insert OID = 1142 (  date_mii		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1082 "1082 23" _null_ _null_ _null_ _null_ date_mii _null_ _null_ _null_ ));
*************** DATA(insert OID = 1195 (  timestamptz_sm
*** 1281,1290 ****
--- 1320,1339 ----
  DESCR("smaller of two");
  DATA(insert OID = 1196 (  timestamptz_larger  PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1184 "1184 1184" _null_ _null_ _null_ _null_ timestamp_larger _null_ _null_ _null_ ));
  DESCR("larger of two");
+ DATA(insert OID = 4051 (  timestamptz_smaller_inv PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1184 "1184 1184" _null_ _null_ _null_ _null_ timestamp_smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 4052 (  timestamptz_larger_inv  PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1184 "1184 1184" _null_ _null_ _null_ _null_ timestamp_larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
  DATA(insert OID = 1197 (  interval_smaller	PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1186 "1186 1186" _null_ _null_ _null_ _null_	interval_smaller _null_ _null_ _null_ ));
  DESCR("smaller of two");
  DATA(insert OID = 1198 (  interval_larger	PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1186 "1186 1186" _null_ _null_ _null_ _null_	interval_larger _null_ _null_ _null_ ));
  DESCR("larger of two");
+ 
+ DATA(insert OID = 4053 (  interval_smaller_inv	PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1186 "1186 1186" _null_ _null_ _null_ _null_	interval_smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 4054 (  interval_larger_inv	PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1186 "1186 1186" _null_ _null_ _null_ _null_	interval_larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ 
  DATA(insert OID = 1199 (  age				PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1186 "1184 1184" _null_ _null_ _null_ _null_	timestamptz_age _null_ _null_ _null_ ));
  DESCR("date difference preserving months and years");
  
*************** DESCR("larger of two");
*** 1318,1323 ****
--- 1367,1378 ----
  DATA(insert OID = 1237 (  int8smaller	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 20 "20 20" _null_ _null_ _null_ _null_ int8smaller _null_ _null_ _null_ ));
  DESCR("smaller of two");
  
+ DATA(insert OID = 4055 (  int8larger_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 20 "20 20" _null_ _null_ _null_ _null_ int8larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 4056 (  int8smaller_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 20 "20 20" _null_ _null_ _null_ _null_ int8smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ 
+ 
  DATA(insert OID = 1238 (  texticregexeq    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "25 25" _null_ _null_ _null_ _null_ texticregexeq _null_ _null_ _null_ ));
  DATA(insert OID = 1239 (  texticregexne    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "25 25" _null_ _null_ _null_ _null_ texticregexne _null_ _null_ _null_ ));
  DATA(insert OID = 1240 (  nameicregexeq    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "19 25" _null_ _null_ _null_ _null_ nameicregexeq _null_ _null_ _null_ ));
*************** DESCR("larger of two");
*** 1374,1379 ****
--- 1429,1439 ----
  DATA(insert OID = 2796 ( tidsmaller		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 27 "27 27" _null_ _null_ _null_ _null_ tidsmaller _null_ _null_ _null_ ));
  DESCR("smaller of two");
  
+ DATA(insert OID = 4057 ( tidlarger_inv		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 27 "27 27" _null_ _null_ _null_ _null_ tidlarger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 4058 ( tidsmaller_inv		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 27 "27 27" _null_ _null_ _null_ _null_ tidsmaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ 
  DATA(insert OID = 1296 (  timedate_pl	   PGNSP PGUID 14 1 0 0 0 f f f f t f i 2 0 1114 "1083 1082" _null_ _null_ _null_ _null_ "select ($2 + $1)" _null_ _null_ _null_ ));
  DATA(insert OID = 1297 (  datetimetz_pl    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1184 "1082 1266" _null_ _null_ _null_ _null_ datetimetz_timestamptz _null_ _null_ _null_ ));
  DATA(insert OID = 1298 (  timetzdate_pl    PGNSP PGUID 14 1 0 0 0 f f f f t f i 2 0 1184 "1266 1082" _null_ _null_ _null_ _null_ "select ($2 + $1)" _null_ _null_ _null_ ));
*************** DESCR("larger of two");
*** 1515,1520 ****
--- 1575,1590 ----
  DATA(insert OID = 1380 (  timetz_smaller   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1266 "1266 1266" _null_ _null_ _null_ _null_ timetz_smaller _null_ _null_ _null_ ));
  DESCR("smaller of two");
  
+ DATA(insert OID = 4059 (  time_larger_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1083 "1083 1083" _null_ _null_ _null_ _null_ time_larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 4060 (  time_smaller_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1083 "1083 1083" _null_ _null_ _null_ _null_ time_smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 4061 (  timetz_larger_inv    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1266 "1266 1266" _null_ _null_ _null_ _null_ timetz_larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 4062 (  timetz_smaller_inv   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1266 "1266 1266" _null_ _null_ _null_ _null_ timetz_smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ 
+ 
  DATA(insert OID = 1381 (  char_length	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 23 "25" _null_ _null_ _null_ _null_ textlen _null_ _null_ _null_ ));
  DESCR("character length");
  
*************** DATA(insert OID = 1766 ( numeric_smaller
*** 2277,2282 ****
--- 2347,2357 ----
  DESCR("smaller of two");
  DATA(insert OID = 1767 ( numeric_larger			PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1700 "1700 1700" _null_ _null_ _null_ _null_	numeric_larger _null_ _null_ _null_ ));
  DESCR("larger of two");
+ DATA(insert OID = 4063 ( numeric_smaller_inv		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1700 "1700 1700" _null_ _null_ _null_ _null_	numeric_smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 4064 ( numeric_larger_inv			PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1700 "1700 1700" _null_ _null_ _null_ _null_	numeric_larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ 
  DATA(insert OID = 1769 ( numeric_cmp			PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 23 "1700 1700" _null_ _null_ _null_ _null_ numeric_cmp _null_ _null_ _null_ ));
  DESCR("less-equal-greater");
  DATA(insert OID = 1771 ( numeric_uminus			PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1700" _null_ _null_ _null_ _null_ numeric_uminus _null_ _null_ _null_ ));
*************** DESCR("larger of two");
*** 2803,2808 ****
--- 2878,2888 ----
  DATA(insert OID = 1966 (  oidsmaller	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 26 "26 26" _null_ _null_ _null_ _null_ oidsmaller _null_ _null_ _null_ ));
  DESCR("smaller of two");
  
+ DATA(insert OID = 4065 (  oidlarger_inv		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 26 "26 26" _null_ _null_ _null_ _null_ oidlarger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 4066 (  oidsmaller_inv	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 26 "26 26" _null_ _null_ _null_ _null_ oidsmaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ 
  DATA(insert OID = 1967 (  timestamptz	   PGNSP PGUID 12 1 0 0 timestamp_transform f f f f t f i 2 0 1184 "1184 23" _null_ _null_ _null_ _null_ timestamptz_scale _null_ _null_ _null_ ));
  DESCR("adjust timestamptz precision");
  DATA(insert OID = 1968 (  time			   PGNSP PGUID 12 1 0 0 time_transform f f f f t f i 2 0 1083 "1083 23" _null_ _null_ _null_ _null_ time_scale _null_ _null_ _null_ ));
*************** DATA(insert OID = 2035 (  timestamp_smal
*** 2864,2869 ****
--- 2944,2955 ----
  DESCR("smaller of two");
  DATA(insert OID = 2036 (  timestamp_larger	PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1114 "1114 1114" _null_ _null_ _null_ _null_	timestamp_larger _null_ _null_ _null_ ));
  DESCR("larger of two");
+ 
+ DATA(insert OID = 4067 (  timestamp_smaller_inv PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1114 "1114 1114" _null_ _null_ _null_ _null_	timestamp_smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 4068 (  timestamp_larger_inv	PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1114 "1114 1114" _null_ _null_ _null_ _null_	timestamp_larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ 
  DATA(insert OID = 2037 (  timezone			PGNSP PGUID 12 1 0 0 0 f f f f t f v 2 0 1266 "25 1266" _null_ _null_ _null_ _null_ timetz_zone _null_ _null_ _null_ ));
  DESCR("adjust time with time zone to new zone");
  DATA(insert OID = 2038 (  timezone			PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1266 "1186 1266" _null_ _null_ _null_ _null_	timetz_izone _null_ _null_ _null_ ));
*************** DATA(insert OID = 3524 (  enum_smaller	P
*** 4254,4259 ****
--- 4340,4350 ----
  DESCR("smaller of two");
  DATA(insert OID = 3525 (  enum_larger	PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 3500 "3500 3500" _null_ _null_ _null_ _null_ enum_larger _null_ _null_ _null_ ));
  DESCR("larger of two");
+ DATA(insert OID = 4073 (  enum_smaller_inv	PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 3500 "3500 3500" _null_ _null_ _null_ _null_ enum_smaller_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ DATA(insert OID = 4074 (  enum_larger_inv	PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 3500 "3500 3500" _null_ _null_ _null_ _null_ enum_larger_inv _null_ _null_ _null_ ));
+ DESCR("inverse aggregate transition function");
+ 
  DATA(insert OID = 3526 (  max			PGNSP PGUID 12 1 0 0 0 t f f f f f i 1 0 3500 "3500" _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
  DESCR("maximum value of all enum input values");
  DATA(insert OID = 3527 (  min			PGNSP PGUID 12 1 0 0 0 t f f f f f i 1 0 3500 "3500" _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
diff --git a/src/include/utils/array.h b/src/include/utils/array.h
index 9bbfaae..43e4973 100644
*** a/src/include/utils/array.h
--- b/src/include/utils/array.h
*************** extern Datum array_upper(PG_FUNCTION_ARG
*** 206,212 ****
--- 206,214 ----
  extern Datum array_length(PG_FUNCTION_ARGS);
  extern Datum array_cardinality(PG_FUNCTION_ARGS);
  extern Datum array_larger(PG_FUNCTION_ARGS);
+ extern Datum array_larger_inv(PG_FUNCTION_ARGS);
  extern Datum array_smaller(PG_FUNCTION_ARGS);
+ extern Datum array_smaller_inv(PG_FUNCTION_ARGS);
  extern Datum generate_subscripts(PG_FUNCTION_ARGS);
  extern Datum generate_subscripts_nodir(PG_FUNCTION_ARGS);
  extern Datum array_fill(PG_FUNCTION_ARGS);
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 031a43a..b869743 100644
*** a/src/include/utils/builtins.h
--- b/src/include/utils/builtins.h
*************** extern Datum enum_ge(PG_FUNCTION_ARGS);
*** 167,173 ****
--- 167,175 ----
  extern Datum enum_gt(PG_FUNCTION_ARGS);
  extern Datum enum_cmp(PG_FUNCTION_ARGS);
  extern Datum enum_smaller(PG_FUNCTION_ARGS);
+ extern Datum enum_smaller_inv(PG_FUNCTION_ARGS);
  extern Datum enum_larger(PG_FUNCTION_ARGS);
+ extern Datum enum_larger_inv(PG_FUNCTION_ARGS);
  extern Datum enum_first(PG_FUNCTION_ARGS);
  extern Datum enum_last(PG_FUNCTION_ARGS);
  extern Datum enum_range_bounds(PG_FUNCTION_ARGS);
*************** extern Datum int42div(PG_FUNCTION_ARGS);
*** 241,249 ****
--- 243,255 ----
  extern Datum int4mod(PG_FUNCTION_ARGS);
  extern Datum int2mod(PG_FUNCTION_ARGS);
  extern Datum int2larger(PG_FUNCTION_ARGS);
+ extern Datum int2larger_inv(PG_FUNCTION_ARGS);
  extern Datum int2smaller(PG_FUNCTION_ARGS);
+ extern Datum int2smaller_inv(PG_FUNCTION_ARGS);
  extern Datum int4larger(PG_FUNCTION_ARGS);
+ extern Datum int4larger_inv(PG_FUNCTION_ARGS);
  extern Datum int4smaller(PG_FUNCTION_ARGS);
+ extern Datum int4smaller_inv(PG_FUNCTION_ARGS);
  
  extern Datum int4and(PG_FUNCTION_ARGS);
  extern Datum int4or(PG_FUNCTION_ARGS);
*************** extern Datum float4abs(PG_FUNCTION_ARGS)
*** 347,358 ****
--- 353,368 ----
  extern Datum float4um(PG_FUNCTION_ARGS);
  extern Datum float4up(PG_FUNCTION_ARGS);
  extern Datum float4larger(PG_FUNCTION_ARGS);
+ extern Datum float4larger_inv(PG_FUNCTION_ARGS);
  extern Datum float4smaller(PG_FUNCTION_ARGS);
+ extern Datum float4smaller_inv(PG_FUNCTION_ARGS);
  extern Datum float8abs(PG_FUNCTION_ARGS);
  extern Datum float8um(PG_FUNCTION_ARGS);
  extern Datum float8up(PG_FUNCTION_ARGS);
  extern Datum float8larger(PG_FUNCTION_ARGS);
+ extern Datum float8larger_inv(PG_FUNCTION_ARGS);
  extern Datum float8smaller(PG_FUNCTION_ARGS);
+ extern Datum float8smaller_inv(PG_FUNCTION_ARGS);
  extern Datum float4pl(PG_FUNCTION_ARGS);
  extern Datum float4mi(PG_FUNCTION_ARGS);
  extern Datum float4mul(PG_FUNCTION_ARGS);
*************** extern Datum oidle(PG_FUNCTION_ARGS);
*** 501,507 ****
--- 511,519 ----
  extern Datum oidge(PG_FUNCTION_ARGS);
  extern Datum oidgt(PG_FUNCTION_ARGS);
  extern Datum oidlarger(PG_FUNCTION_ARGS);
+ extern Datum oidlarger_inv(PG_FUNCTION_ARGS);
  extern Datum oidsmaller(PG_FUNCTION_ARGS);
+ extern Datum oidsmaller_inv(PG_FUNCTION_ARGS);
  extern Datum oidvectorin(PG_FUNCTION_ARGS);
  extern Datum oidvectorout(PG_FUNCTION_ARGS);
  extern Datum oidvectorrecv(PG_FUNCTION_ARGS);
*************** extern Datum tidgt(PG_FUNCTION_ARGS);
*** 707,713 ****
--- 719,727 ----
  extern Datum tidge(PG_FUNCTION_ARGS);
  extern Datum bttidcmp(PG_FUNCTION_ARGS);
  extern Datum tidlarger(PG_FUNCTION_ARGS);
+ extern Datum tidlarger_inv(PG_FUNCTION_ARGS);
  extern Datum tidsmaller(PG_FUNCTION_ARGS);
+ extern Datum tidsmaller_inv(PG_FUNCTION_ARGS);
  extern Datum currtid_byreloid(PG_FUNCTION_ARGS);
  extern Datum currtid_byrelname(PG_FUNCTION_ARGS);
  
*************** extern Datum bpchargt(PG_FUNCTION_ARGS);
*** 730,736 ****
--- 744,752 ----
  extern Datum bpcharge(PG_FUNCTION_ARGS);
  extern Datum bpcharcmp(PG_FUNCTION_ARGS);
  extern Datum bpchar_larger(PG_FUNCTION_ARGS);
+ extern Datum bpchar_larger_inv(PG_FUNCTION_ARGS);
  extern Datum bpchar_smaller(PG_FUNCTION_ARGS);
+ extern Datum bpchar_smaller_inv(PG_FUNCTION_ARGS);
  extern Datum bpcharlen(PG_FUNCTION_ARGS);
  extern Datum bpcharoctetlen(PG_FUNCTION_ARGS);
  extern Datum hashbpchar(PG_FUNCTION_ARGS);
*************** extern Datum text_le(PG_FUNCTION_ARGS);
*** 770,776 ****
--- 786,794 ----
  extern Datum text_gt(PG_FUNCTION_ARGS);
  extern Datum text_ge(PG_FUNCTION_ARGS);
  extern Datum text_larger(PG_FUNCTION_ARGS);
+ extern Datum text_larger_inv(PG_FUNCTION_ARGS);
  extern Datum text_smaller(PG_FUNCTION_ARGS);
+ extern Datum text_smaller_inv(PG_FUNCTION_ARGS);
  extern Datum text_pattern_lt(PG_FUNCTION_ARGS);
  extern Datum text_pattern_le(PG_FUNCTION_ARGS);
  extern Datum text_pattern_gt(PG_FUNCTION_ARGS);
*************** extern Datum numeric_div_trunc(PG_FUNCTI
*** 980,986 ****
--- 998,1006 ----
  extern Datum numeric_mod(PG_FUNCTION_ARGS);
  extern Datum numeric_inc(PG_FUNCTION_ARGS);
  extern Datum numeric_smaller(PG_FUNCTION_ARGS);
+ extern Datum numeric_smaller_inv(PG_FUNCTION_ARGS);
  extern Datum numeric_larger(PG_FUNCTION_ARGS);
+ extern Datum numeric_larger_inv(PG_FUNCTION_ARGS);
  extern Datum numeric_fac(PG_FUNCTION_ARGS);
  extern Datum numeric_sqrt(PG_FUNCTION_ARGS);
  extern Datum numeric_exp(PG_FUNCTION_ARGS);
diff --git a/src/include/utils/cash.h b/src/include/utils/cash.h
index 3a491f9..4e184cc 100644
*** a/src/include/utils/cash.h
--- b/src/include/utils/cash.h
*************** extern Datum int2_mul_cash(PG_FUNCTION_A
*** 60,66 ****
--- 60,68 ----
  extern Datum cash_div_int2(PG_FUNCTION_ARGS);
  
  extern Datum cashlarger(PG_FUNCTION_ARGS);
+ extern Datum cashlarger_inv(PG_FUNCTION_ARGS);
  extern Datum cashsmaller(PG_FUNCTION_ARGS);
+ extern Datum cashsmaller_inv(PG_FUNCTION_ARGS);
  
  extern Datum cash_words(PG_FUNCTION_ARGS);
  
diff --git a/src/include/utils/date.h b/src/include/utils/date.h
index 622aa19..9f459ac 100644
*** a/src/include/utils/date.h
--- b/src/include/utils/date.h
*************** extern Datum date_cmp(PG_FUNCTION_ARGS);
*** 108,114 ****
--- 108,116 ----
  extern Datum date_sortsupport(PG_FUNCTION_ARGS);
  extern Datum date_finite(PG_FUNCTION_ARGS);
  extern Datum date_larger(PG_FUNCTION_ARGS);
+ extern Datum date_larger_inv(PG_FUNCTION_ARGS);
  extern Datum date_smaller(PG_FUNCTION_ARGS);
+ extern Datum date_smaller_inv(PG_FUNCTION_ARGS);
  extern Datum date_mi(PG_FUNCTION_ARGS);
  extern Datum date_pli(PG_FUNCTION_ARGS);
  extern Datum date_mii(PG_FUNCTION_ARGS);
*************** extern Datum time_cmp(PG_FUNCTION_ARGS);
*** 168,174 ****
--- 170,178 ----
  extern Datum time_hash(PG_FUNCTION_ARGS);
  extern Datum overlaps_time(PG_FUNCTION_ARGS);
  extern Datum time_larger(PG_FUNCTION_ARGS);
+ extern Datum time_larger_inv(PG_FUNCTION_ARGS);
  extern Datum time_smaller(PG_FUNCTION_ARGS);
+ extern Datum time_smaller_inv(PG_FUNCTION_ARGS);
  extern Datum time_mi_time(PG_FUNCTION_ARGS);
  extern Datum timestamp_time(PG_FUNCTION_ARGS);
  extern Datum timestamptz_time(PG_FUNCTION_ARGS);
*************** extern Datum timetz_cmp(PG_FUNCTION_ARGS
*** 195,201 ****
--- 199,207 ----
  extern Datum timetz_hash(PG_FUNCTION_ARGS);
  extern Datum overlaps_timetz(PG_FUNCTION_ARGS);
  extern Datum timetz_larger(PG_FUNCTION_ARGS);
+ extern Datum timetz_larger_inv(PG_FUNCTION_ARGS);
  extern Datum timetz_smaller(PG_FUNCTION_ARGS);
+ extern Datum timetz_smaller_inv(PG_FUNCTION_ARGS);
  extern Datum timetz_time(PG_FUNCTION_ARGS);
  extern Datum time_timetz(PG_FUNCTION_ARGS);
  extern Datum timestamptz_timetz(PG_FUNCTION_ARGS);
diff --git a/src/include/utils/int8.h b/src/include/utils/int8.h
index d63e3a9..d102ccb 100644
*** a/src/include/utils/int8.h
--- b/src/include/utils/int8.h
*************** extern Datum int8inc(PG_FUNCTION_ARGS);
*** 77,83 ****
--- 77,85 ----
  extern Datum int8inc_any(PG_FUNCTION_ARGS);
  extern Datum int8inc_float8_float8(PG_FUNCTION_ARGS);
  extern Datum int8larger(PG_FUNCTION_ARGS);
+ extern Datum int8larger_inv(PG_FUNCTION_ARGS);
  extern Datum int8smaller(PG_FUNCTION_ARGS);
+ extern Datum int8smaller_inv(PG_FUNCTION_ARGS);
  
  extern Datum int8and(PG_FUNCTION_ARGS);
  extern Datum int8or(PG_FUNCTION_ARGS);
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index 2731c6a..4f6673c 100644
*** a/src/include/utils/timestamp.h
--- b/src/include/utils/timestamp.h
*************** extern Datum timestamp_cmp(PG_FUNCTION_A
*** 111,117 ****
--- 111,119 ----
  extern Datum timestamp_sortsupport(PG_FUNCTION_ARGS);
  extern Datum timestamp_hash(PG_FUNCTION_ARGS);
  extern Datum timestamp_smaller(PG_FUNCTION_ARGS);
+ extern Datum timestamp_smaller_inv(PG_FUNCTION_ARGS);
  extern Datum timestamp_larger(PG_FUNCTION_ARGS);
+ extern Datum timestamp_larger_inv(PG_FUNCTION_ARGS);
  
  extern Datum timestamp_eq_timestamptz(PG_FUNCTION_ARGS);
  extern Datum timestamp_ne_timestamptz(PG_FUNCTION_ARGS);
*************** extern Datum interval_finite(PG_FUNCTION
*** 151,157 ****
--- 153,161 ----
  extern Datum interval_cmp(PG_FUNCTION_ARGS);
  extern Datum interval_hash(PG_FUNCTION_ARGS);
  extern Datum interval_smaller(PG_FUNCTION_ARGS);
+ extern Datum interval_smaller_inv(PG_FUNCTION_ARGS);
  extern Datum interval_larger(PG_FUNCTION_ARGS);
+ extern Datum interval_larger_inv(PG_FUNCTION_ARGS);
  extern Datum interval_justify_interval(PG_FUNCTION_ARGS);
  extern Datum interval_justify_hours(PG_FUNCTION_ARGS);
  extern Datum interval_justify_days(PG_FUNCTION_ARGS);
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index e3eba47..3c4ad7f 100644
*** a/src/test/regress/expected/window.out
--- b/src/test/regress/expected/window.out
*************** DROP FUNCTION logging_sfunc_nonstrict(te
*** 1305,1310 ****
--- 1305,1403 ----
  -- Test the MIN and MAX inverse transition functions
  --
  --
+ SELECT v,MAX(v) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,10),(2,20),(3,30),(4,40)) v(i,v)
+ WINDOW w AS (ORDER BY i ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING);
+  v  | max | min 
+ ----+-----+-----
+  10 |  20 |  10
+  20 |  30 |  20
+  30 |  40 |  30
+  40 |  40 |  40
+ (4 rows)
+ 
+ SELECT v,MAX(v) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,10::int),(2,20),(3,NULL),(4,40)) v(i,v)
+ WINDOW w AS (ORDER BY i ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING);
+  v  | max | min 
+ ----+-----+-----
+  10 |  20 |  10
+  20 |  20 |  20
+     |  40 |  40
+  40 |  40 |  40
+ (4 rows)
+ 
+ SELECT v,MAX(v) FILTER(WHERE v <> 40) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,10::int),(2,20),(3,30),(4,40)) v(i,v)
+ WINDOW w AS (ORDER BY i ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING);
+  v  | max | min 
+ ----+-----+-----
+  10 |  20 |  10
+  20 |  30 |  20
+  30 |  30 |  30
+  40 |     |  40
+ (4 rows)
+ 
+ SELECT v,MAX(v) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,40::int),(2,40),(3,20),(4,NULL),(5,10)) v(i,v)
+ WINDOW w AS (ORDER BY i RANGE BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING);
+  v  | max | min 
+ ----+-----+-----
+  40 |  40 |  10
+  40 |  40 |  10
+  20 |  20 |  10
+     |  10 |  10
+  10 |  10 |  10
+ (5 rows)
+ 
+ SELECT v,MAX(CASE WHEN v <= 20 THEN NULL ELSE v END) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,40::int),(2,40),(3,20),(4,NULL),(5,10)) v(i,v)
+ WINDOW w AS (ORDER BY i RANGE BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING);
+  v  | max | min 
+ ----+-----+-----
+  40 |  40 |  10
+  40 |  40 |  10
+  20 |     |  10
+     |     |  10
+  10 |     |  10
+ (5 rows)
+ 
+ SELECT v,MAX(v) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,'ad'),(2,'ab'),(3,'ad'),(4,'aa'),(5,'ae')) v(i,v)
+ WINDOW w AS (ORDER BY i ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING);
+  v  | max | min 
+ ----+-----+-----
+  ad | ad  | ab
+  ab | ad  | ab
+  ad | ad  | aa
+  aa | ae  | aa
+  ae | ae  | ae
+ (5 rows)
+ 
+ SELECT v,MAX(v) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,'ad'),(2,'ab'),(3,'ad'),(4,'aa'),(5,'ae')) v(i,v)
+ WINDOW w AS (ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING);
+  v  | max | min 
+ ----+-----+-----
+  ad | ad  | ab
+  ab | ad  | ab
+  ad | ad  | aa
+  aa | ae  | aa
+  ae | ae  | ae
+ (5 rows)
+ 
+ SELECT v,p,MAX(v) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,100,'ad'),(2,100,'ab'),(3,200,'ad'),(4,200,'aa'),(5,100,'ae')) v(i,p,v)
+ WINDOW w AS (PARTITION BY p ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING);
+  v  |  p  | max | min 
+ ----+-----+-----+-----
+  ad | 100 | ae  | ab
+  ab | 100 | ae  | ab
+  ae | 100 | ae  | ae
+  ad | 200 | ad  | aa
+  aa | 200 | aa  | aa
+ (5 rows)
+ 
  --
  --
  -- Tests of the collecting inverse transition functions
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index bd8dbdc..bde2a49 100644
*** a/src/test/regress/sql/window.sql
--- b/src/test/regress/sql/window.sql
*************** DROP FUNCTION logging_sfunc_nonstrict(te
*** 488,493 ****
--- 488,525 ----
  --
  --
  
+ SELECT v,MAX(v) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,10),(2,20),(3,30),(4,40)) v(i,v)
+ WINDOW w AS (ORDER BY i ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING);
+ 
+ SELECT v,MAX(v) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,10::int),(2,20),(3,NULL),(4,40)) v(i,v)
+ WINDOW w AS (ORDER BY i ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING);
+ 
+ SELECT v,MAX(v) FILTER(WHERE v <> 40) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,10::int),(2,20),(3,30),(4,40)) v(i,v)
+ WINDOW w AS (ORDER BY i ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING);
+ 
+ SELECT v,MAX(v) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,40::int),(2,40),(3,20),(4,NULL),(5,10)) v(i,v)
+ WINDOW w AS (ORDER BY i RANGE BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING);
+ 
+ SELECT v,MAX(CASE WHEN v <= 20 THEN NULL ELSE v END) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,40::int),(2,40),(3,20),(4,NULL),(5,10)) v(i,v)
+ WINDOW w AS (ORDER BY i RANGE BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING);
+ 
+ SELECT v,MAX(v) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,'ad'),(2,'ab'),(3,'ad'),(4,'aa'),(5,'ae')) v(i,v)
+ WINDOW w AS (ORDER BY i ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING);
+ 
+ SELECT v,MAX(v) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,'ad'),(2,'ab'),(3,'ad'),(4,'aa'),(5,'ae')) v(i,v)
+ WINDOW w AS (ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING);
+ 
+ SELECT v,p,MAX(v) OVER w,MIN(v) OVER w
+ FROM (VALUES(1,100,'ad'),(2,100,'ab'),(3,200,'ad'),(4,200,'aa'),(5,100,'ae')) v(i,p,v)
+ WINDOW w AS (PARTITION BY p ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING);
+ 
  --
  --
  -- Tests of the collecting inverse transition functions