
term_variables_count(?Term, -N)

   Succeeds if N is the number of distinct variables in Term.

Arguments
   Term                Prolog term.
   N                   Variable or integer.

Type
   Term Manipulation

Description

   This predicate counts the number of different variables in Term.
   Repeat occurrences of variables are ignored.

   As usual, attributed variables are also considered variables.

   This predicate can handle cyclic terms.



Modes and Determinism
   term_variables_count(?, -) is det

Examples
   
    term_variables_count(f(bar), N)       gives N=0
    term_variables_count(f(X,b,Y), N)     gives N=2
    term_variables_count(f(X,Y,X), N)     gives N=2
    term_variables_count(X, N)            gives N=1
    X=f(X), term_variables_count(X, N)    gives N=0
    X=f(X,Y), term_variables_count(X, N)  gives N=1


See Also
   term_variables / 2, term_variables_array / 2, nonground / 1, nonground / 2, nonground / 3, nonvar / 1, var / 1
