:- use_module(library(prolog_xref)).(can be autoloaded)
- xref_meta(+Head, -Called) is semidet
- xref_meta_src(+Head, -Called, +Src) is semidet
- True when Called is a list of terms called from Head. Each element in Called can be of the form Term+Int, which means that Term must be extended with Int additional arguments. The variant xref_meta/3 first queries the local context.