is true if its argument is not true
not( test_predicate )
void(Goal) (i) Term to be tested.
This is a standard prolog built-in. Not succeeds if a call
() to Goal would not.
NOTE: there are to versions of not(). If the argument is bound at compile time, i.e. is not a variable, the compiler handles not. If the argument is a variable, not uses call(), thus the same restrictions apply!
read(X), ( char(X), write("Character"),nl ; integer(X), write("Integer"),nl ; not( isname ), write("Error"),nl,! ; write("Is a Token\n") ).
No runtime errors.
prolog-process, client-server, object