Cubicle 1.1.2 documentation and source : Types.Atom.has

let rec has_vars vs = function
    | True | False -> false
    | Comp (x, _, y) -> has_vars_term vs x || has_vars_term vs y
    | Ite (sa, a1, a2) ->
       SAtom.exists (has_vars vs) sa || has_vars vs a1 || has_vars vs a2