fact: Fixpoint eval {V:Type0} (vs : Vars V) (e : Expr V) : R := match e with | Var v => vs v | Zero => 0 | One => 1 | Plus a b => eval vs a + eval vs b | Mult a b => eval vs a * eval vs b | Neg a => almost_negate (eval vs a) end.
imports: HoTT.Classes.interfaces.abstract_algebra