?- zdd_misc:subst_atomic([a-b, b-a], f(a, b), F). ?- zdd_misc:subst_atomic([a-b, b-a], f(c, d), F).
subst_atomic([a-b, b-a], f(a, b), F)
subst_atomic([a-b, b-a], f(c, d), F)