- See also
- 
library(terms)provides similar predicates and is probably 
more wide-spread than this library.
This is a SWI-Prolog implementation of the corresponding Quintus 
library, based on the generalised arg/3 
predicate of SWI-Prolog.
- [semidet]contains_term(+Sub, 
+Term)
- 
Succeeds if Sub is contained in Term (=, 
deterministically)
- [det]contains_var(+Sub, 
+Term)
- 
Succeeds if Sub is contained in Term (==, 
deterministically)
- free_of_term(+Sub, 
+Term)
- 
Succeeds of Sub does not unify to any subterm of Term
- free_of_var(+Sub, 
+Term)
- 
Succeeds of Sub is not equal (==) to any subterm 
of Term
- occurrences_of_term(+SubTerm, 
+Term, ?Count)
- 
Count the number of SubTerms in Term
- occurrences_of_var(+SubTerm, 
+Term, ?Count)
- 
Count the number of SubTerms in Term
- sub_term(-Sub, 
+Term)
- 
Generates (on backtracking) all subterms of Term.
- sub_var(-Sub, 
+Term)
- 
Generates (on backtracking) all subterms (==) of Term.