let set' ~(recompute: bool) ?(p_preserving:bool = false)
(subst: subst) (var: Var.var) (var_offset: int) (term: Term.term) (term_offset: int) : subst =
set ~recompute:recompute ~p_preserving:p_preserving
subst (make_var var var_offset) (make_term term term_offset)