XML: NOT Operator !
From FSDeveloper Wiki
NOT Operator !
Explanation of the ! Operator courtesy Tom Aguilo:
The NOT Operator, ! (negation sign) acts like a toggle operator. It works by extracting the last value on the stack and converting it:
- to 0 when it is >= 1 or <= -1 (equivalent to logical FALSE, or "zero" ) - to 1 when it is > -1 and < 1 (equivalent to logical TRUE, or "not zero" )
