The type checking predicates

integer/1, var/1, nonvar/1

integer(Term)

var(Term)

nonvar(Term)

Check the type of a Term

Remarks

integer(Term) succeeds if the Term can be unified with integer value.

var(Term) succeeds if the Term is free variable.

nonvar(Term) succeeds if the Term is bound.

Example

A is 3

var(A)

No

nonvar(A)

Yes

integer(A)

Yes