NG - Not Greater Than
The Not Greater Than (NG) operator checks that Operand 1 is not greater than Operand 2. 
Statement:			If the value of PC 100 is negative, set it to 0.
||Line||CMD||OT||Operand 1||OPER||OT||Operand2||OT||Operand3||If Goto||	Else GoTo
00010	IF	PC	100	NG	N	-1			100	99999
00100	LET	PC	100	EQ	N	0			99999	
99999	EXIT								99999	

Here, the UserCalc compares if the value in Operand1 (PC100) to the value in Operand 2 (-1). If PC100 is NOT greater than -1 and thereby a negative value, the UserCalc goes to Line 00100 to make the Operand1 value 0.