• !expr is the logical NOT function. It gives False if expr is True, and True if it is False.
can be input in StandardForm
. The character
can be entered as !
• Not gives symbolic results when necessary, applying various simplification rules to them.
• If you are using Mathematica with a text-based front end, then you cannot use the notation !expr for Not[expr] if it appears at the very beginning of a line. In this case, !expr is interpreted as a shell escape.
• New in Version 1; modified in 3.