diff --git a/library/data/sigma/thms.lean b/library/data/sigma/thms.lean index 0bc91aa30..6309da403 100644 --- a/library/data/sigma/thms.lean +++ b/library/data/sigma/thms.lean @@ -12,27 +12,27 @@ namespace sigma destruct u (λx y H, H) H theorem dpair_eq {a₁ a₂ : A} {b₁ : B a₁} {b₂ : B a₂} (H₁ : a₁ = a₂) (H₂ : eq.rec_on H₁ b₁ = b₂) : - dpair a₁ b₁ = dpair a₂ b₂ := + ⟨a₁, b₁⟩ = ⟨a₂, b₂⟩ := dcongr_arg2 dpair H₁ H₂ theorem dpair_heq {a : A} {a' : A'} {b : B a} {b' : B' a'} - (HB : B == B') (Ha : a == a') (Hb : b == b') : dpair a b == dpair a' b' := + (HB : B == B') (Ha : a == a') (Hb : b == b') : ⟨a, b⟩ == ⟨a', b'⟩ := hcongr_arg4 @dpair (heq.type_eq Ha) HB Ha Hb protected theorem equal {p₁ p₂ : Σa : A, B a} : - ∀(H₁ : dpr1 p₁ = dpr1 p₂) (H₂ : eq.rec_on H₁ (dpr2 p₁) = dpr2 p₂), p₁ = p₂ := + ∀(H₁ : p₁.1 = p₂.1) (H₂ : eq.rec_on H₁ p₁.2 = p₂.2), p₁ = p₂ := destruct p₁ (take a₁ b₁, destruct p₂ (take a₂ b₂ H₁ H₂, dpair_eq H₁ H₂)) protected theorem hequal {p : Σa : A, B a} {p' : Σa' : A', B' a'} (HB : B == B') : - ∀(H₁ : dpr1 p == dpr1 p') (H₂ : dpr2 p == dpr2 p'), p == p' := + ∀(H₁ : p.1 == p'.1) (H₂ : p.2 == p'.2), p == p' := destruct p (take a₁ b₁, destruct p' (take a₂ b₂ H₁ H₂, dpair_heq HB H₁ H₂)) protected definition is_inhabited [instance] (H₁ : inhabited A) (H₂ : inhabited (B (default A))) : inhabited (sigma B) := - inhabited.destruct H₁ (λa, inhabited.destruct H₂ (λb, inhabited.mk (dpair (default A) b))) + inhabited.destruct H₁ (λa, inhabited.destruct H₂ (λb, inhabited.mk ⟨default A, b⟩)) theorem eq_rec_dpair_commute {C : Πa, B a → Type} {a a' : A} (H : a = a') (b : B a) (c : C a b) : - eq.rec_on H (dpair b c) = dpair (eq.rec_on H b) (eq.rec_on (dcongr_arg2 C H rfl) c) := + eq.rec_on H ⟨b, c⟩ = ⟨eq.rec_on H b, eq.rec_on (dcongr_arg2 C H rfl) c⟩ := eq.drec_on H (dpair_eq rfl (!eq.rec_on_id⁻¹)) variables {C : Πa, B a → Type} {D : Πa b, C a b → Type} diff --git a/library/init/sigma.lean b/library/init/sigma.lean index 2ec84d5a5..113a77334 100644 --- a/library/init/sigma.lean +++ b/library/init/sigma.lean @@ -10,17 +10,16 @@ dpair :: (dpr1 : A) (dpr2 : B dpr1) notation `Σ` binders `,` r:(scoped P, sigma P) := r namespace sigma - - notation `dpr₁` := dpr1 - notation `dpr₂` := dpr2 + notation `dpr₁` := dpr1 + notation `dpr₂` := dpr2 namespace ops postfix `.1`:(max+1) := dpr1 postfix `.2`:(max+1) := dpr2 - notation `⟨` t:(foldr `,` (e r, sigma.dpair e r)) `⟩`:0 := t --input ⟨ ⟩ as \< \> + notation `⟨`:max t:(foldr `,` (e r, dpair e r)) `⟩`:0 := t --input ⟨ ⟩ as \< \> end ops - open well_founded + open ops well_founded section variables {A : Type} {B : A → Type} @@ -29,8 +28,8 @@ namespace sigma -- Lexicographical order based on Ra and Rb inductive lex : sigma B → sigma B → Prop := - left : ∀{a₁ b₁} a₂ b₂, Ra a₁ a₂ → lex (dpair a₁ b₁) (dpair a₂ b₂), - right : ∀a {b₁ b₂}, Rb a b₁ b₂ → lex (dpair a b₁) (dpair a b₂) + left : ∀{a₁ b₁} a₂ b₂, Ra a₁ a₂ → lex ⟨a₁, b₁⟩ ⟨a₂, b₂⟩, + right : ∀a {b₁ b₂}, Rb a b₁ b₂ → lex ⟨a, b₁⟩ ⟨a, b₂⟩ end context @@ -53,23 +52,23 @@ namespace sigma : f a b c == f a' b' c' := hcongr (hcongr_arg2 f Ha Hb) (hcongr_arg2 D Ha Hb) Hc - definition lex.accessible {a} (aca : acc Ra a) (acb : ∀a, well_founded (Rb a)) : ∀ (b : B a), acc (lex Ra Rb) (dpair a b) := + definition lex.accessible {a} (aca : acc Ra a) (acb : ∀a, well_founded (Rb a)) : ∀ (b : B a), acc (lex Ra Rb) ⟨a, b⟩ := acc.rec_on aca - (λxa aca (iHa : ∀y, Ra y xa → ∀b : B y, acc (lex Ra Rb) (dpair y b)), + (λxa aca (iHa : ∀y, Ra y xa → ∀b : B y, acc (lex Ra Rb) ⟨y, b⟩), λb : B xa, acc.rec_on (acb xa b) (λxb acb - (iHb : ∀y, Rb xa y xb → acc (lex Ra Rb) (dpair xa y)), - acc.intro (dpair xa xb) (λp (lt : p ≺ (dpair xa xb)), + (iHb : ∀y, Rb xa y xb → acc (lex Ra Rb) ⟨xa, y⟩), + acc.intro ⟨xa, xb⟩ (λp (lt : p ≺ ⟨xa, xb⟩), have aux : xa = xa → xb == xb → acc (lex Ra Rb) p, from - @lex.rec_on A B Ra Rb (λp₁ p₂, dpr1 p₂ = xa → dpr2 p₂ == xb → acc (lex Ra Rb) p₁) - p (dpair xa xb) lt + @lex.rec_on A B Ra Rb (λp₁ p₂, p₂.1 = xa → p₂.2 == xb → acc (lex Ra Rb) p₁) + p ⟨xa, xb⟩ lt (λa₁ b₁ a₂ b₂ (H : Ra a₁ a₂) (eq₂ : a₂ = xa) (eq₃ : b₂ == xb), - show acc (lex Ra Rb) (dpair a₁ b₁), from + show acc (lex Ra Rb) ⟨a₁, b₁⟩, from have Ra₁ : Ra a₁ xa, from eq.rec_on eq₂ H, iHa a₁ Ra₁ b₁) (λa b₁ b₂ (H : Rb a b₁ b₂) (eq₂ : a = xa) (eq₃ : b₂ == xb), -- TODO(Leo): cleanup this proof - show acc (lex Ra Rb) (dpair a b₁), from + show acc (lex Ra Rb) ⟨a, b₁⟩, from let b₁' : B xa := eq.rec_on eq₂ b₁ in have aux₁ : b₁ == b₁', from heq.symm (eq_rec_heq eq₂ b₁), @@ -77,11 +76,11 @@ namespace sigma heq.to_eq (hcongr_arg3 Rb eq₂ aux₁ eq₃), have aux₃ : Rb xa b₁' xb, from eq.rec_on aux₂ H, - have aux₄ : acc (lex Ra Rb) (dpair xa b₁'), from + have aux₄ : acc (lex Ra Rb) ⟨xa, b₁'⟩, from iHb b₁' aux₃, - have aux₅ : ∀ (b₁ b₂ : B a) (H₁ : a = a) (H₂ : b₁ == b₂), acc (lex Ra Rb) (dpair a b₁) → acc (lex Ra Rb) (dpair a b₂), from + have aux₅ : ∀ (b₁ b₂ : B a) (H₁ : a = a) (H₂ : b₁ == b₂), acc (lex Ra Rb) ⟨a, b₁⟩ → acc (lex Ra Rb) ⟨a, b₂⟩, from λ b₁ b₂ H₁ H₂ Ha, eq.rec_on (heq.to_eq H₂) Ha, - have aux₆ : ∀ (b₁ : B xa) (b₂ : B a) (H₁ : a = xa) (H₂ : b₁ == b₂), acc (lex Ra Rb) (dpair xa b₁) → acc (lex Ra Rb) (dpair a b₂), from + have aux₆ : ∀ (b₁ : B xa) (b₂ : B a) (H₁ : a = xa) (H₂ : b₁ == b₂), acc (lex Ra Rb) ⟨xa, b₁⟩ → acc (lex Ra Rb) ⟨a, b₂⟩, from eq.rec_on eq₂ aux₅, aux₆ b₁' b₁ eq₂ (heq.symm aux₁) aux₄), aux rfl !heq.refl)))