Class PropositionalVariables: Type := {
  Var: Type
}.Class PropositionalVariables: Type := {
  Var: Type
}.Inductive expr {Sigma: PropositionalVariables}: Type :=
  | andp : expr -> expr -> expr
  | orp : expr -> expr -> expr
  | impp : expr -> expr -> expr
  | sepcon : expr -> expr -> expr
  | wand : expr -> expr -> expr
  | emp : expr
  | falsep : expr
  | varp : Var -> expr.Inductive expr {Sigma: PropositionalVariables}: Type :=
  | andp : expr -> expr -> expr
  | orp : expr -> expr -> expr
  | impp : expr -> expr -> expr
  | sepcon : expr -> expr -> expr
  | wand : expr -> expr -> expr
  | emp : expr
  | falsep : expr
  | varp : Var -> expr.Inductive expr {Sigma: PropositionalVariables}: Type :=
  | andp : expr -> expr -> expr
  | orp : expr -> expr -> expr
  | impp : expr -> expr -> expr
  | sepcon : expr -> expr -> expr
  | wand : expr -> expr -> expr
  | emp : expr
  | falsep : expr
  | varp : Var -> expr.Inductive expr {Sigma: PropositionalVariables}: Type :=
  | andp : expr -> expr -> expr
  | orp : expr -> expr -> expr
  | impp : expr -> expr -> expr
  | sepcon : expr -> expr -> expr
  | wand : expr -> expr -> expr
  | emp : expr
  | falsep : expr
  | varp : Var -> expr.Inductive expr {Sigma: PropositionalVariables}: Type :=
  | andp : expr -> expr -> expr
  | orp : expr -> expr -> expr
  | impp : expr -> expr -> expr
  | sepcon : expr -> expr -> expr
  | wand : expr -> expr -> expr
  | emp : expr
  | falsep : expr
  | varp : Var -> expr.Inductive expr {Sigma: PropositionalVariables}: Type :=
  | andp : expr -> expr -> expr
  | orp : expr -> expr -> expr
  | impp : expr -> expr -> expr
  | sepcon : expr -> expr -> expr
  | wand : expr -> expr -> expr
  | emp : expr
  | falsep : expr
  | varp : Var -> expr.Inductive expr {Sigma: PropositionalVariables}: Type :=
  | andp : expr -> expr -> expr
  | orp : expr -> expr -> expr
  | impp : expr -> expr -> expr
  | sepcon : expr -> expr -> expr
  | wand : expr -> expr -> expr
  | emp : expr
  | falsep : expr
  | varp : Var -> expr.Inductive expr {Sigma: PropositionalVariables}: Type :=
  | andp : expr -> expr -> expr
  | orp : expr -> expr -> expr
  | impp : expr -> expr -> expr
  | sepcon : expr -> expr -> expr
  | wand : expr -> expr -> expr
  | emp : expr
  | falsep : expr
  | varp : Var -> expr.Inductive expr {Sigma: PropositionalVariables}: Type :=
  | andp : expr -> expr -> expr
  | orp : expr -> expr -> expr
  | impp : expr -> expr -> expr
  | sepcon : expr -> expr -> expr
  | wand : expr -> expr -> expr
  | emp : expr
  | falsep : expr
  | varp : Var -> expr.Definition expr_eqb {Sigma: PropositionalVariables} (eqb: Var -> Var -> bool): expr Sigma -> expr Sigma -> bool :=
  fix expr_eqb x1 x2 :=
    match x1, x2 with
    | andp y1 z1, andp y2 z2 => andb (expr_eqb y1 y2) (expr_eqb z1 z2)
    | orp y1 z1, orp y2 z2 => andb (expr_eqb y1 y2) (expr_eqb z1 z2)
    | impp y1 z1, impp y2 z2 => andb (expr_eqb y1 y2) (expr_eqb z1 z2)
    | sepcon y1 z1, sepcon y2 z2 => andb (expr_eqb y1 y2) (expr_eqb z1 z2)
    | wand y1 z1, wand y2 z2 => andb (expr_eqb y1 y2) (expr_eqb z1 z2)
    | emp, emp => true
    | falsep, falsep => true
    | varp p, varp q => eqb p q
    | _, _ => false
    end.

(* Specifications: *)
Lemma expr_eqb_true {Sigma: PropositionalVariables} (eqb: Var -> Var -> bool): (forall p q, eqb p q = true <-> p = q) -> (forall x y, expr_eqb eqb x y = true <-> x = y).