/- Copyright (c) 2014 Microsoft Corporation. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Author: Leonardo de Moura -/ import logic.eq namespace bool local attribute bor [reducible] local attribute band [reducible] theorem dichotomy (b : bool) : b = ff ∨ b = tt := sorry -- by rec_simp attribute [simp] theorem cond_ff {A : Type} (t e : A) : cond ff t e = e := rfl attribute [simp] theorem cond_tt {A : Type} (t e : A) : cond tt t e = t := rfl theorem eq_tt_of_ne_ff : ∀ {a : bool}, a ≠ ff → a = tt := sorry -- by rec_simp theorem eq_ff_of_ne_tt : ∀ {a : bool}, a ≠ tt → a = ff := sorry -- by rec_simp theorem absurd_of_eq_ff_of_eq_tt {B : Prop} {a : bool} (H₁ : a = ff) (H₂ : a = tt) : B := sorry -- by rec_simp attribute [simp] theorem tt_bor (a : bool) : bor tt a = tt := rfl notation a || b := bor a b attribute [simp] theorem bor_tt (a : bool) : a || tt = tt := sorry -- by rec_simp attribute [simp] theorem ff_bor (a : bool) : ff || a = a := sorry -- by rec_simp attribute [simp] theorem bor_ff (a : bool) : a || ff = a := sorry -- by rec_simp attribute [simp] theorem bor_self (a : bool) : a || a = a := sorry -- by rec_simp attribute [simp] theorem bor_comm (a b : bool) : a || b = b || a := sorry -- by rec_simp attribute [simp] theorem bor_assoc (a b c : bool) : (a || b) || c = a || (b || c) := sorry -- by rec_simp attribute [simp] theorem bor_left_comm (a b c : bool) : a || (b || c) = b || (a || c) := sorry -- by rec_simp theorem or_of_bor_eq {a b : bool} : a || b = tt → a = tt ∨ b = tt := sorry -- by rec_simp theorem bor_inl {a b : bool} (H : a = tt) : a || b = tt := sorry -- by rec_simp theorem bor_inr {a b : bool} (H : b = tt) : a || b = tt := sorry -- by rec_simp attribute [simp] theorem ff_band (a : bool) : ff && a = ff := rfl attribute [simp] theorem tt_band (a : bool) : tt && a = a := sorry -- by rec_simp attribute [simp] theorem band_ff (a : bool) : a && ff = ff := sorry -- by rec_simp attribute [simp] theorem band_tt (a : bool) : a && tt = a := sorry -- by rec_simp attribute [simp] theorem band_self (a : bool) : a && a = a := sorry -- by rec_simp attribute [simp] theorem band_comm (a b : bool) : a && b = b && a := sorry -- by rec_simp attribute [simp] theorem band_assoc (a b c : bool) : (a && b) && c = a && (b && c) := sorry -- by rec_simp attribute [simp] theorem band_left_comm (a b c : bool) : a && (b && c) = b && (a && c) := sorry -- by rec_simp theorem band_elim_left {a b : bool} (H : a && b = tt) : a = tt := sorry -- by rec_simp theorem band_intro {a b : bool} (H₁ : a = tt) (H₂ : b = tt) : a && b = tt := sorry -- by rec_simp theorem band_elim_right {a b : bool} (H : a && b = tt) : b = tt := sorry -- by rec_simp attribute [simp] theorem bnot_false : bnot ff = tt := rfl attribute [simp] theorem bnot_true : bnot tt = ff := rfl attribute [simp] theorem bnot_bnot (a : bool) : bnot (bnot a) = a := sorry -- by rec_simp theorem eq_tt_of_bnot_eq_ff {a : bool} : bnot a = ff → a = tt := sorry -- by rec_simp theorem eq_ff_of_bnot_eq_tt {a : bool} : bnot a = tt → a = ff := sorry -- by rec_simp definition bxor : bool → bool → bool | ff ff := ff | ff tt := tt | tt ff := tt | tt tt := ff attribute [simp] lemma ff_bxor_ff : bxor ff ff = ff := rfl attribute [simp] lemma ff_bxor_tt : bxor ff tt = tt := rfl attribute [simp] lemma tt_bxor_ff : bxor tt ff = tt := rfl attribute [simp] lemma tt_bxor_tt : bxor tt tt = ff := rfl attribute [simp] lemma bxor_self (a : bool) : bxor a a = ff := sorry -- by rec_simp attribute [simp] lemma bxor_ff (a : bool) : bxor a ff = a := sorry -- by rec_simp attribute [simp] lemma bxor_tt (a : bool) : bxor a tt = bnot a := sorry -- by rec_simp attribute [simp] lemma ff_bxor (a : bool) : bxor ff a = a := sorry -- by rec_simp attribute [simp] lemma tt_bxor (a : bool) : bxor tt a = bnot a := sorry -- by rec_simp attribute [simp] lemma bxor_comm (a b : bool) : bxor a b = bxor b a := sorry -- by rec_simp attribute [simp] lemma bxor_assoc (a b c : bool) : bxor (bxor a b) c = bxor a (bxor b c) := sorry -- by rec_simp attribute [simp] lemma bxor_left_comm (a b c : bool) : bxor a (bxor b c) = bxor b (bxor a c) := sorry -- by rec_simp end bool