AMOSi:Not

an example can be found on AMOSPro_Examples:Examples/H-5/Help_53.AMOS

Switches every binary digit in your number to a different state. It's commonly used as part of a IF..THEN statement to reverse the effect of the tests.

Print Bin$(Not %1010,4)
If Not (A=1 and B=2) Then Print "Successful"