not

Pops one item from the stack, treats it as a boolean value, 'nots' it, and pushes 0 or 1 back to the stack.

If the item is TRUE, 0 is pushed to the stack. If the item is FALSE, 1 is pushed to the stack.

True not Trace     #prints out 0 (False) to the tracelog
False not Trace    #prints out 1 (True) to the tracelog