occurrences_of

Documentation
- Reference manual
  - The SWI-Prolog library
    - library(occurs): Finding and counting sub-terms
- Packages

Availability::- use_module(library(occurs)).(can be autoloaded)

[det]occurrences_of_var(@SubTerm, @Term, ?Count)

Count the number of SubTerms in Term that are equal to SubTerm. Equality is tested using ==/2. Can be used to count the occurrences of a particular variable in Term.

See also: occurrences_of_term/3 for a unification (=/2) based variant.