url
stringclasses
147 values
commit
stringclasses
147 values
file_path
stringlengths
7
101
full_name
stringlengths
1
94
start
stringlengths
6
10
end
stringlengths
6
11
tactic
stringlengths
1
11.2k
state_before
stringlengths
3
2.09M
state_after
stringlengths
6
2.09M
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_and_iff_or_not
[10, 1]
[28, 4]
exact h
case neg.h p q r : Prop hnand : ¬(p ∧ q) h : ¬p ⊢ ¬p
no goals
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_and_iff_or_not
[10, 1]
[28, 4]
intros hnor hand
case mpr p q r : Prop ⊢ ¬p ∨ ¬q → ¬(p ∧ q)
case mpr p q r : Prop hnor : ¬p ∨ ¬q hand : p ∧ q ⊢ False
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_and_iff_or_not
[10, 1]
[28, 4]
rcases hand with ⟨hp, hq⟩
case mpr p q r : Prop hnor : ¬p ∨ ¬q hand : p ∧ q ⊢ False
case mpr.intro p q r : Prop hnor : ¬p ∨ ¬q hp : p hq : q ⊢ False
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_and_iff_or_not
[10, 1]
[28, 4]
cases hnor with | inl hnp => exact hnp hp | inr hnq => exact hnq hq
case mpr.intro p q r : Prop hnor : ¬p ∨ ¬q hp : p hq : q ⊢ False
no goals
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_and_iff_or_not
[10, 1]
[28, 4]
exact hnp hp
case mpr.intro.inl p q r : Prop hp : p hq : q hnp : ¬p ⊢ False
no goals
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_and_iff_or_not
[10, 1]
[28, 4]
exact hnq hq
case mpr.intro.inr p q r : Prop hp : p hq : q hnq : ¬q ⊢ False
no goals
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
constructor
p q r : Prop ⊢ ¬(p ∨ q) ↔ ¬p ∧ ¬q
case mp p q r : Prop ⊢ ¬(p ∨ q) → ¬p ∧ ¬q case mpr p q r : Prop ⊢ ¬p ∧ ¬q → ¬(p ∨ q)
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
{ intro hnor constructor { intro hp exact hnor (Or.inl hp) } { intro hq exact hnor (Or.inr hq) } }
case mp p q r : Prop ⊢ ¬(p ∨ q) → ¬p ∧ ¬q case mpr p q r : Prop ⊢ ¬p ∧ ¬q → ¬(p ∨ q)
case mpr p q r : Prop ⊢ ¬p ∧ ¬q → ¬(p ∨ q)
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
{ intros hnand hor rcases hnand with ⟨hnp, hnq⟩ cases hor with | inl hp => exact hnp hp | inr hq => exact hnq hq }
case mpr p q r : Prop ⊢ ¬p ∧ ¬q → ¬(p ∨ q)
no goals
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
intro hnor
case mp p q r : Prop ⊢ ¬(p ∨ q) → ¬p ∧ ¬q
case mp p q r : Prop hnor : ¬(p ∨ q) ⊢ ¬p ∧ ¬q
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
constructor
case mp p q r : Prop hnor : ¬(p ∨ q) ⊢ ¬p ∧ ¬q
case mp.left p q r : Prop hnor : ¬(p ∨ q) ⊢ ¬p case mp.right p q r : Prop hnor : ¬(p ∨ q) ⊢ ¬q
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
{ intro hp exact hnor (Or.inl hp) }
case mp.left p q r : Prop hnor : ¬(p ∨ q) ⊢ ¬p case mp.right p q r : Prop hnor : ¬(p ∨ q) ⊢ ¬q
case mp.right p q r : Prop hnor : ¬(p ∨ q) ⊢ ¬q
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
{ intro hq exact hnor (Or.inr hq) }
case mp.right p q r : Prop hnor : ¬(p ∨ q) ⊢ ¬q
no goals
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
intro hp
case mp.left p q r : Prop hnor : ¬(p ∨ q) ⊢ ¬p
case mp.left p q r : Prop hnor : ¬(p ∨ q) hp : p ⊢ False
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
exact hnor (Or.inl hp)
case mp.left p q r : Prop hnor : ¬(p ∨ q) hp : p ⊢ False
no goals
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
intro hq
case mp.right p q r : Prop hnor : ¬(p ∨ q) ⊢ ¬q
case mp.right p q r : Prop hnor : ¬(p ∨ q) hq : q ⊢ False
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
exact hnor (Or.inr hq)
case mp.right p q r : Prop hnor : ¬(p ∨ q) hq : q ⊢ False
no goals
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
intros hnand hor
case mpr p q r : Prop ⊢ ¬p ∧ ¬q → ¬(p ∨ q)
case mpr p q r : Prop hnand : ¬p ∧ ¬q hor : p ∨ q ⊢ False
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
rcases hnand with ⟨hnp, hnq⟩
case mpr p q r : Prop hnand : ¬p ∧ ¬q hor : p ∨ q ⊢ False
case mpr.intro p q r : Prop hor : p ∨ q hnp : ¬p hnq : ¬q ⊢ False
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
cases hor with | inl hp => exact hnp hp | inr hq => exact hnq hq
case mpr.intro p q r : Prop hor : p ∨ q hnp : ¬p hnq : ¬q ⊢ False
no goals
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
exact hnp hp
case mpr.intro.inl p q r : Prop hnp : ¬p hnq : ¬q hp : p ⊢ False
no goals
https://github.com/aronerben/lean4-playground.git
5efced915ecee24cd723d28d00aa63f9c7ea0a9c
meetings/Foundations.lean
not_or_iff_and_not
[30, 1]
[50, 4]
exact hnq hq
case mpr.intro.inr p q r : Prop hnp : ¬p hnq : ¬q hq : q ⊢ False
no goals
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
MotivatedMoves/Moves/TreeRewriteOrd.lean
MotivatedTree.funext_ord
[204, 1]
[204, 113]
exact h
α : Type u β : Type v inst✝ : Preorder β f g : α → β h : ∀ (a : α), f a ≤ g a ⊢ f ≤ g
no goals
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
Tests/Demo.lean
Cantor
[4, 1]
[12, 33]
motivated_proof tree_rewrite_def [1, 1, 1, 2] tree_push_neg [1, 1] lib_rewrite [1, 1, 1, 2, 0, 1] Set.ext_iff [1, 1, 1, 1, 1, 2] tree_push_neg [1, 1, 1, 1] lib_rewrite [1, 1, 2, 0, 1] not_iff [1, 1, 1, 1, 1] unify_forall_exists [1, 1, 1] lib_apply refl [1, 1, 1, 1, 2]
⊢ ∀ (X : Type u) (f : X → Set X), ¬Function.Surjective f
no goals
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
Tests/Demo.lean
Cantor
[4, 1]
[12, 33]
tree_rewrite_def [1, 1, 1, 2]
⊢ ∀ X : Type u, f : X → Set X⠀ ¬Function.Surjective f
⊢ ∀ X : Type u, f : X → Set X⠀ ¬∀ b⋆ : Set X, ∃ a : X⠀ f a = b⋆
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
Tests/Demo.lean
Cantor
[4, 1]
[12, 33]
tree_push_neg [1, 1]
⊢ ∀ X : Type u, f : X → Set X⠀ ¬∀ b⋆ : Set X, ∃ a : X⠀ f a = b⋆
⊢ ∀ X : Type u, f : X → Set X, ∃ x• : Set X, ∀ x_1 : X⠀ ¬f x_1 = x•
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
Tests/Demo.lean
Cantor
[4, 1]
[12, 33]
lib_rewrite [1, 1, 1, 2, 0, 1] Set.ext_iff [1, 1, 1, 1, 1, 2]
⊢ ∀ X : Type u, f : X → Set X, ∃ x• : Set X, ∀ x_1 : X⠀ ¬f x_1 = x•
⊢ ∀ X : Type u, f : X → Set X, ∃ x• : Set X, ∀ x_1 : X⠀ ¬(∀ x_2⋆ : X⠀ x_2⋆ ∈ f x_1 ↔ x_2⋆ ∈ x•)
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
Tests/Demo.lean
Cantor
[4, 1]
[12, 33]
tree_push_neg [1, 1, 1, 1]
⊢ ∀ X : Type u, f : X → Set X, ∃ x• : Set X, ∀ x_1 : X⠀ ¬(∀ x_2⋆ : X⠀ x_2⋆ ∈ f x_1 ↔ x_2⋆ ∈ x•)
⊢ ∀ X : Type u, f : X → Set X, ∃ x• : Set X, ∀ x_1 : X, ∃ x_2• : X⠀ ¬(x_2• ∈ f x_1 ↔ x_2• ∈ x•)
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
Tests/Demo.lean
Cantor
[4, 1]
[12, 33]
lib_rewrite [1, 1, 2, 0, 1] not_iff [1, 1, 1, 1, 1]
⊢ ∀ X : Type u, f : X → Set X, ∃ x• : Set X, ∀ x_1 : X, ∃ x_2• : X⠀ ¬(x_2• ∈ f x_1 ↔ x_2• ∈ x•)
⊢ ∀ X : Type u, f : X → Set X, ∃ x• : Set X, ∀ x_1 : X, ∃ x_2• : X⠀ ¬x_2• ∈ f x_1 ↔ x_2• ∈ x•
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
Tests/Demo.lean
Cantor
[4, 1]
[12, 33]
unify_forall_exists [1, 1, 1]
⊢ ∀ X : Type u, f : X → Set X, ∃ x• : Set X, ∀ x_1 : X, ∃ x_2• : X⠀ ¬x_2• ∈ f x_1 ↔ x_2• ∈ x•
⊢ ∀ X : Type u, f : X → Set X, ∃ x• : Set X, ∀ a : X⠀ ¬a ∈ f a ↔ a ∈ x•
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
Tests/Demo.lean
Cantor
[4, 1]
[12, 33]
lib_apply refl [1, 1, 1, 1, 2]
⊢ ∀ X : Type u, f : X → Set X, ∃ x• : Set X, ∀ a : X⠀ ¬a ∈ f a ↔ a ∈ x•
no goals
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
MotivatedMoves/Moves/TreeRewrite.lean
MotivatedTree.imp_exists_iff
[157, 1]
[166, 19]
apply Iff.intro
α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop ⊢ Imp p (_root_.Exists q) ↔ ∃ a, p → q a
case mp α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop ⊢ Imp p (_root_.Exists q) → ∃ a, p → q a case mpr α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop ⊢ (∃ a, p → q a) → Imp p (_root_.Exists q)
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
MotivatedMoves/Moves/TreeRewrite.lean
MotivatedTree.imp_exists_iff
[157, 1]
[166, 19]
by_cases p
case mp α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop ⊢ Imp p (_root_.Exists q) → ∃ a, p → q a case mpr α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop ⊢ (∃ a, p → q a) → Imp p (_root_.Exists q)
case pos α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop h✝ : p ⊢ Imp p (_root_.Exists q) → ∃ a, p → q a case neg α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop h✝ : ¬p ⊢ Imp p (_root_.Exists q) → ∃ a, p → q a case mpr α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop ⊢ (∃ a, p → q a) → Imp p (_root_.Exists q)
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
MotivatedMoves/Moves/TreeRewrite.lean
MotivatedTree.imp_exists_iff
[157, 1]
[166, 19]
intro g
case pos α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop h✝ : p ⊢ Imp p (_root_.Exists q) → ∃ a, p → q a
case pos α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop h✝ : p g : Imp p (_root_.Exists q) ⊢ ∃ a, p → q a
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
MotivatedMoves/Moves/TreeRewrite.lean
MotivatedTree.imp_exists_iff
[157, 1]
[166, 19]
have ⟨a, g⟩ := g ‹p›
case pos α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop h✝ : p g : Imp p (_root_.Exists q) ⊢ ∃ a, p → q a
case pos α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop h✝ : p g✝ : Imp p (_root_.Exists q) a : α g : q a ⊢ ∃ a, p → q a
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
MotivatedMoves/Moves/TreeRewrite.lean
MotivatedTree.imp_exists_iff
[157, 1]
[166, 19]
exact ⟨a, fun _ => g⟩
case pos α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop h✝ : p g✝ : Imp p (_root_.Exists q) a : α g : q a ⊢ ∃ a, p → q a
no goals
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
MotivatedMoves/Moves/TreeRewrite.lean
MotivatedTree.imp_exists_iff
[157, 1]
[166, 19]
intro _
case neg α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop h✝ : ¬p ⊢ Imp p (_root_.Exists q) → ∃ a, p → q a
case neg α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop h✝ : ¬p a✝ : Imp p (_root_.Exists q) ⊢ ∃ a, p → q a
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
MotivatedMoves/Moves/TreeRewrite.lean
MotivatedTree.imp_exists_iff
[157, 1]
[166, 19]
intro ⟨a, h⟩ g
case mpr α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop ⊢ (∃ a, p → q a) → Imp p (_root_.Exists q)
case mpr α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop a : α h : p → q a g : p ⊢ _root_.Exists q
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
MotivatedMoves/Moves/TreeRewrite.lean
MotivatedTree.imp_exists_iff
[157, 1]
[166, 19]
exact ⟨a, h g⟩
case mpr α : Sort u_1 inst : Nonempty α p : Prop q : α → Prop a : α h : p → q a g : p ⊢ _root_.Exists q
no goals
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
Tests/Moves/TreeApply.lean
cantor_end
[13, 1]
[16, 43]
make_tree
⊢ ∀ (X : Type u) (f : X → Set X), ∃ a, ∀ (a_1 : X), a_1 ∉ f a_1 ↔ a_1 ∈ a
⊢ MotivatedTree.Forall (Type u) fun X => MotivatedTree.Forall (X → Set X) fun f => MotivatedTree.Exists (Set X) fun a => MotivatedTree.Forall X fun a_1 => MotivatedTree.Not (a_1 ∈ f a_1) ↔ a_1 ∈ a
https://github.com/Human-Oriented-ATP/lean-tactics.git
a62b1d3dd89deaf243ff9536cb31a318ea91c628
Tests/Moves/TreeApply.lean
cantor_end
[13, 1]
[16, 43]
lib_apply [1,1,1,1] refl [1, 1, 1, 1, 2]
⊢ MotivatedTree.Forall (Type u) fun X => MotivatedTree.Forall (X → Set X) fun f => MotivatedTree.Exists (Set X) fun a => MotivatedTree.Forall X fun a_1 => MotivatedTree.Not (a_1 ∈ f a_1) ↔ a_1 ∈ a
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.two_mul
[46, 1]
[48, 10]
ring
n : ℕ ⊢ 2 * n = n + n
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.add_sub_again
[50, 9]
[55, 61]
induction m with | zero => simp | succ m' ih => rw [Nat.succ_add, Nat.succ_sub_succ, ih]
m n : ℕ ⊢ m + n - m = n
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.add_sub_again
[50, 9]
[55, 61]
simp
case zero n : ℕ ⊢ Nat.zero + n - Nat.zero = n
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.add_sub_again
[50, 9]
[55, 61]
rw [Nat.succ_add, Nat.succ_sub_succ, ih]
case succ n m' : ℕ ih : m' + n - m' = n ⊢ Nat.succ m' + n - Nat.succ m' = n
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.sub_one_add
[57, 9]
[64, 12]
induction n with | zero => aesop | succ => rw [Nat.succ_add] aesop
n m : ℕ h : ¬n = 0 ⊢ n - 1 + m = n + m - 1
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.sub_one_add
[57, 9]
[64, 12]
aesop
case zero m : ℕ h : ¬Nat.zero = 0 ⊢ Nat.zero - 1 + m = Nat.zero + m - 1
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.sub_one_add
[57, 9]
[64, 12]
rw [Nat.succ_add]
case succ m n_1 : ℕ n_ih : ¬n_1 = 0 → n_1 - 1 + m = n_1 + m - 1 h : ¬Nat.succ n_1 = 0 ⊢ Nat.succ n_1 - 1 + m = Nat.succ n_1 + m - 1
case succ m n_1 : ℕ n_ih : ¬n_1 = 0 → n_1 - 1 + m = n_1 + m - 1 h : ¬Nat.succ n_1 = 0 ⊢ Nat.succ n_1 - 1 + m = Nat.succ (n_1 + m) - 1
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.sub_one_add
[57, 9]
[64, 12]
aesop
case succ m n_1 : ℕ n_ih : ¬n_1 = 0 → n_1 - 1 + m = n_1 + m - 1 h : ¬Nat.succ n_1 = 0 ⊢ Nat.succ n_1 - 1 + m = Nat.succ (n_1 + m) - 1
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.plus_lt_plus_right
[66, 9]
[73, 37]
apply Iff.intro
l m n : ℕ ⊢ m + l < n + l ↔ m < n
case mp l m n : ℕ ⊢ m + l < n + l → m < n case mpr l m n : ℕ ⊢ m < n → m + l < n + l
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.plus_lt_plus_right
[66, 9]
[73, 37]
{ intro h apply Nat.lt_of_add_lt_add_right h }
case mp l m n : ℕ ⊢ m + l < n + l → m < n case mpr l m n : ℕ ⊢ m < n → m + l < n + l
case mpr l m n : ℕ ⊢ m < n → m + l < n + l
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.plus_lt_plus_right
[66, 9]
[73, 37]
{ intro h apply Nat.add_lt_add_right h }
case mpr l m n : ℕ ⊢ m < n → m + l < n + l
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.plus_lt_plus_right
[66, 9]
[73, 37]
intro h
case mp l m n : ℕ ⊢ m + l < n + l → m < n
case mp l m n : ℕ h : m + l < n + l ⊢ m < n
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.plus_lt_plus_right
[66, 9]
[73, 37]
apply Nat.lt_of_add_lt_add_right h
case mp l m n : ℕ h : m + l < n + l ⊢ m < n
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.plus_lt_plus_right
[66, 9]
[73, 37]
intro h
case mpr l m n : ℕ ⊢ m < n → m + l < n + l
case mpr l m n : ℕ h : m < n ⊢ m + l < n + l
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.plus_lt_plus_right
[66, 9]
[73, 37]
apply Nat.add_lt_add_right h
case mpr l m n : ℕ h : m < n ⊢ m + l < n + l
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.plus_le_plus_right
[75, 9]
[82, 37]
apply Iff.intro
l m n : ℕ ⊢ m + l ≤ n + l ↔ m ≤ n
case mp l m n : ℕ ⊢ m + l ≤ n + l → m ≤ n case mpr l m n : ℕ ⊢ m ≤ n → m + l ≤ n + l
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.plus_le_plus_right
[75, 9]
[82, 37]
{ intro h apply Nat.le_of_add_le_add_right h }
case mp l m n : ℕ ⊢ m + l ≤ n + l → m ≤ n case mpr l m n : ℕ ⊢ m ≤ n → m + l ≤ n + l
case mpr l m n : ℕ ⊢ m ≤ n → m + l ≤ n + l
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.plus_le_plus_right
[75, 9]
[82, 37]
{ intro h apply Nat.add_le_add_right h }
case mpr l m n : ℕ ⊢ m ≤ n → m + l ≤ n + l
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.plus_le_plus_right
[75, 9]
[82, 37]
intro h
case mp l m n : ℕ ⊢ m + l ≤ n + l → m ≤ n
case mp l m n : ℕ h : m + l ≤ n + l ⊢ m ≤ n
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.plus_le_plus_right
[75, 9]
[82, 37]
apply Nat.le_of_add_le_add_right h
case mp l m n : ℕ h : m + l ≤ n + l ⊢ m ≤ n
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.plus_le_plus_right
[75, 9]
[82, 37]
intro h
case mpr l m n : ℕ ⊢ m ≤ n → m + l ≤ n + l
case mpr l m n : ℕ h : m ≤ n ⊢ m + l ≤ n + l
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.plus_le_plus_right
[75, 9]
[82, 37]
apply Nat.add_le_add_right h
case mpr l m n : ℕ h : m ≤ n ⊢ m + l ≤ n + l
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_lt_imp
[84, 9]
[96, 22]
apply Iff.intro
m n : ℕ p : Prop hge : m ≥ n ⊢ m < n → p ↔ True
case mp m n : ℕ p : Prop hge : m ≥ n ⊢ (m < n → p) → True case mpr m n : ℕ p : Prop hge : m ≥ n ⊢ True → m < n → p
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_lt_imp
[84, 9]
[96, 22]
{ intro himp apply True.intro }
case mp m n : ℕ p : Prop hge : m ≥ n ⊢ (m < n → p) → True case mpr m n : ℕ p : Prop hge : m ≥ n ⊢ True → m < n → p
case mpr m n : ℕ p : Prop hge : m ≥ n ⊢ True → m < n → p
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_lt_imp
[84, 9]
[96, 22]
{ intro htrue intro hlt have hle : n ≤ m := hge rw [←Nat.not_lt_eq] at hle apply False.elim exact hle hlt }
case mpr m n : ℕ p : Prop hge : m ≥ n ⊢ True → m < n → p
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_lt_imp
[84, 9]
[96, 22]
intro himp
case mp m n : ℕ p : Prop hge : m ≥ n ⊢ (m < n → p) → True
case mp m n : ℕ p : Prop hge : m ≥ n himp : m < n → p ⊢ True
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_lt_imp
[84, 9]
[96, 22]
apply True.intro
case mp m n : ℕ p : Prop hge : m ≥ n himp : m < n → p ⊢ True
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_lt_imp
[84, 9]
[96, 22]
intro htrue
case mpr m n : ℕ p : Prop hge : m ≥ n ⊢ True → m < n → p
case mpr m n : ℕ p : Prop hge : m ≥ n htrue : True ⊢ m < n → p
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_lt_imp
[84, 9]
[96, 22]
intro hlt
case mpr m n : ℕ p : Prop hge : m ≥ n htrue : True ⊢ m < n → p
case mpr m n : ℕ p : Prop hge : m ≥ n htrue : True hlt : m < n ⊢ p
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_lt_imp
[84, 9]
[96, 22]
have hle : n ≤ m := hge
case mpr m n : ℕ p : Prop hge : m ≥ n htrue : True hlt : m < n ⊢ p
case mpr m n : ℕ p : Prop hge : m ≥ n htrue : True hlt : m < n hle : n ≤ m ⊢ p
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_lt_imp
[84, 9]
[96, 22]
rw [←Nat.not_lt_eq] at hle
case mpr m n : ℕ p : Prop hge : m ≥ n htrue : True hlt : m < n hle : n ≤ m ⊢ p
case mpr m n : ℕ p : Prop hge : m ≥ n htrue : True hlt : m < n hle : ¬m < n ⊢ p
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_lt_imp
[84, 9]
[96, 22]
apply False.elim
case mpr m n : ℕ p : Prop hge : m ≥ n htrue : True hlt : m < n hle : ¬m < n ⊢ p
case mpr.h m n : ℕ p : Prop hge : m ≥ n htrue : True hlt : m < n hle : ¬m < n ⊢ False
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_lt_imp
[84, 9]
[96, 22]
exact hle hlt
case mpr.h m n : ℕ p : Prop hge : m ≥ n htrue : True hlt : m < n hle : ¬m < n ⊢ False
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.lt_succ
[98, 9]
[103, 31]
apply Iff.intro
m n : ℕ ⊢ Nat.succ m < Nat.succ n ↔ m < n
case mp m n : ℕ ⊢ Nat.succ m < Nat.succ n → m < n case mpr m n : ℕ ⊢ m < n → Nat.succ m < Nat.succ n
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.lt_succ
[98, 9]
[103, 31]
{ apply Nat.lt_of_succ_lt_succ }
case mp m n : ℕ ⊢ Nat.succ m < Nat.succ n → m < n case mpr m n : ℕ ⊢ m < n → Nat.succ m < Nat.succ n
case mpr m n : ℕ ⊢ m < n → Nat.succ m < Nat.succ n
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.lt_succ
[98, 9]
[103, 31]
{ apply Nat.succ_lt_succ }
case mpr m n : ℕ ⊢ m < n → Nat.succ m < Nat.succ n
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.lt_succ
[98, 9]
[103, 31]
apply Nat.lt_of_succ_lt_succ
case mp m n : ℕ ⊢ Nat.succ m < Nat.succ n → m < n
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.lt_succ
[98, 9]
[103, 31]
apply Nat.succ_lt_succ
case mpr m n : ℕ ⊢ m < n → Nat.succ m < Nat.succ n
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_succ
[105, 9]
[110, 31]
apply Iff.intro
m n : ℕ ⊢ Nat.succ m ≤ Nat.succ n ↔ m ≤ n
case mp m n : ℕ ⊢ Nat.succ m ≤ Nat.succ n → m ≤ n case mpr m n : ℕ ⊢ m ≤ n → Nat.succ m ≤ Nat.succ n
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_succ
[105, 9]
[110, 31]
{ apply Nat.le_of_succ_le_succ }
case mp m n : ℕ ⊢ Nat.succ m ≤ Nat.succ n → m ≤ n case mpr m n : ℕ ⊢ m ≤ n → Nat.succ m ≤ Nat.succ n
case mpr m n : ℕ ⊢ m ≤ n → Nat.succ m ≤ Nat.succ n
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_succ
[105, 9]
[110, 31]
{ apply Nat.succ_le_succ }
case mpr m n : ℕ ⊢ m ≤ n → Nat.succ m ≤ Nat.succ n
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_succ
[105, 9]
[110, 31]
apply Nat.le_of_succ_le_succ
case mp m n : ℕ ⊢ Nat.succ m ≤ Nat.succ n → m ≤ n
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Nat.le_succ
[105, 9]
[110, 31]
apply Nat.succ_le_succ
case mpr m n : ℕ ⊢ m ≤ n → Nat.succ m ≤ Nat.succ n
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.neg_neg
[115, 9]
[132, 14]
apply funext
⊢ Int.neg ∘ Int.neg = id
case h ⊢ ∀ (x : ℤ), (Int.neg ∘ Int.neg) x = id x
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.neg_neg
[115, 9]
[132, 14]
intro i
case h ⊢ ∀ (x : ℤ), (Int.neg ∘ Int.neg) x = id x
case h i : ℤ ⊢ (Int.neg ∘ Int.neg) i = id i
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.neg_neg
[115, 9]
[132, 14]
simp
case h i : ℤ ⊢ (Int.neg ∘ Int.neg) i = id i
case h i : ℤ ⊢ Int.neg (Int.neg i) = i
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.neg_neg
[115, 9]
[132, 14]
cases i with | ofNat n => { simp [Int.neg] cases n { simp } { simp [Int.negOfNat] } } | negSucc n => { simp [Int.neg] have hnp1 : (↑n + 1 : ℤ) = ↑(n + 1) := by simp rw [hnp1] rfl }
case h i : ℤ ⊢ Int.neg (Int.neg i) = i
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.neg_neg
[115, 9]
[132, 14]
simp [Int.neg]
case h.ofNat n : ℕ ⊢ Int.neg (Int.neg (Int.ofNat n)) = Int.ofNat n
case h.ofNat n : ℕ ⊢ (match Int.negOfNat n with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = ↑n
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.neg_neg
[115, 9]
[132, 14]
cases n
case h.ofNat n : ℕ ⊢ (match Int.negOfNat n with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = ↑n
case h.ofNat.zero ⊢ (match Int.negOfNat Nat.zero with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = ↑Nat.zero case h.ofNat.succ n_1 : ℕ ⊢ (match Int.negOfNat (Nat.succ n_1) with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = ↑(Nat.succ n_1)
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.neg_neg
[115, 9]
[132, 14]
{ simp }
case h.ofNat.zero ⊢ (match Int.negOfNat Nat.zero with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = ↑Nat.zero case h.ofNat.succ n_1 : ℕ ⊢ (match Int.negOfNat (Nat.succ n_1) with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = ↑(Nat.succ n_1)
case h.ofNat.succ n_1 : ℕ ⊢ (match Int.negOfNat (Nat.succ n_1) with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = ↑(Nat.succ n_1)
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.neg_neg
[115, 9]
[132, 14]
{ simp [Int.negOfNat] }
case h.ofNat.succ n_1 : ℕ ⊢ (match Int.negOfNat (Nat.succ n_1) with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = ↑(Nat.succ n_1)
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.neg_neg
[115, 9]
[132, 14]
simp
case h.ofNat.zero ⊢ (match Int.negOfNat Nat.zero with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = ↑Nat.zero
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.neg_neg
[115, 9]
[132, 14]
simp [Int.negOfNat]
case h.ofNat.succ n_1 : ℕ ⊢ (match Int.negOfNat (Nat.succ n_1) with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = ↑(Nat.succ n_1)
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.neg_neg
[115, 9]
[132, 14]
simp [Int.neg]
case h.negSucc n : ℕ ⊢ Int.neg (Int.neg (Int.negSucc n)) = Int.negSucc n
case h.negSucc n : ℕ ⊢ (match ↑n + 1 with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = Int.negSucc n
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.neg_neg
[115, 9]
[132, 14]
have hnp1 : (↑n + 1 : ℤ) = ↑(n + 1) := by simp
case h.negSucc n : ℕ ⊢ (match ↑n + 1 with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = Int.negSucc n
case h.negSucc n : ℕ hnp1 : ↑n + 1 = ↑(n + 1) ⊢ (match ↑n + 1 with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = Int.negSucc n
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.neg_neg
[115, 9]
[132, 14]
rw [hnp1]
case h.negSucc n : ℕ hnp1 : ↑n + 1 = ↑(n + 1) ⊢ (match ↑n + 1 with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = Int.negSucc n
case h.negSucc n : ℕ hnp1 : ↑n + 1 = ↑(n + 1) ⊢ (match ↑(n + 1) with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = Int.negSucc n
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.neg_neg
[115, 9]
[132, 14]
rfl
case h.negSucc n : ℕ hnp1 : ↑n + 1 = ↑(n + 1) ⊢ (match ↑(n + 1) with | Int.ofNat n => Int.negOfNat n | Int.negSucc n => ↑n + 1) = Int.negSucc n
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.neg_neg
[115, 9]
[132, 14]
simp
n : ℕ ⊢ ↑n + 1 = ↑(n + 1)
no goals
https://github.com/BrownCS1951x/fpv2023.git
9aaf6b5c454aa9a70fc4e6807adf3123b001ea66
LoVe/LoVelib.lean
LoVe.Int.zero_eq_mul
[136, 9]
[140, 26]
rw [eq_comm]
a b : ℤ ⊢ 0 = a * b ↔ a = 0 ∨ b = 0
a b : ℤ ⊢ a * b = 0 ↔ a = 0 ∨ b = 0