/// Test equality of real values allowing for NaN, +Inf, -Inf
/// :returns: TRUE if bath values are the same special values or performs a delta comparison
FUNCTION FPU_UnrealEquals : BOOL
VAR_INPUT
	rl1 : REAL;
	rl2 : REAL;
	delta : REAL;
END_VAR


IF NOT FPU.IsRealNumber(rl1) OR NOT FPU.IsRealNumber(rl2) THEN
	FPU_UnrealEquals S= FPU.IsRealNaN(rl1) AND FPU.IsRealNaN(rl2);
	FPU_UnrealEquals S= FPU.IsRealNegInfinity(rl1) AND FPU.IsRealNegInfinity(rl2);
	FPU_UnrealEquals S= FPU.IsRealPosInfinity(rl1) AND FPU.IsRealPosInfinity(rl2);
ELSE
	FPU_UnrealEquals := ABS(rl1 - rl2) <= delta;
END_IF