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move_right_nim_heq (o : ordinal) : (nim o).move_right == λ i : o.out.α, nim (typein (<) i)
by { rw nim_def, refl }
lemma
pgame.move_right_nim_heq
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_left_moves_nim {o : ordinal} : set.Iio o ≃ (nim o).left_moves
(enum_iso_out o).to_equiv.trans (equiv.cast (left_moves_nim o).symm)
def
pgame.to_left_moves_nim
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "equiv.cast", "ordinal", "set.Iio" ]
Turns an ordinal less than `o` into a left move for `nim o` and viceversa.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_right_moves_nim {o : ordinal} : set.Iio o ≃ (nim o).right_moves
(enum_iso_out o).to_equiv.trans (equiv.cast (right_moves_nim o).symm)
def
pgame.to_right_moves_nim
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "equiv.cast", "ordinal", "set.Iio" ]
Turns an ordinal less than `o` into a right move for `nim o` and viceversa.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_left_moves_nim_symm_lt {o : ordinal} (i : (nim o).left_moves) : ↑(to_left_moves_nim.symm i) < o
(to_left_moves_nim.symm i).prop
theorem
pgame.to_left_moves_nim_symm_lt
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_right_moves_nim_symm_lt {o : ordinal} (i : (nim o).right_moves) : ↑(to_right_moves_nim.symm i) < o
(to_right_moves_nim.symm i).prop
theorem
pgame.to_right_moves_nim_symm_lt
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
move_left_nim' {o : ordinal.{u}} (i) : (nim o).move_left i = nim (to_left_moves_nim.symm i).val
(congr_heq (move_left_nim_heq o).symm (cast_heq _ i)).symm
lemma
pgame.move_left_nim'
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "congr_heq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
move_left_nim {o : ordinal} (i) : (nim o).move_left (to_left_moves_nim i) = nim i
by simp
lemma
pgame.move_left_nim
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
move_right_nim' {o : ordinal} (i) : (nim o).move_right i = nim (to_right_moves_nim.symm i).val
(congr_heq (move_right_nim_heq o).symm (cast_heq _ i)).symm
lemma
pgame.move_right_nim'
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "congr_heq", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
move_right_nim {o : ordinal} (i) : (nim o).move_right (to_right_moves_nim i) = nim i
by simp
lemma
pgame.move_right_nim
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
left_moves_nim_rec_on {o : ordinal} {P : (nim o).left_moves → Sort*} (i : (nim o).left_moves) (H : ∀ a < o, P $ to_left_moves_nim ⟨a, H⟩) : P i
by { rw ←to_left_moves_nim.apply_symm_apply i, apply H }
def
pgame.left_moves_nim_rec_on
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "ordinal" ]
A recursion principle for left moves of a nim game.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
right_moves_nim_rec_on {o : ordinal} {P : (nim o).right_moves → Sort*} (i : (nim o).right_moves) (H : ∀ a < o, P $ to_right_moves_nim ⟨a, H⟩) : P i
by { rw ←to_right_moves_nim.apply_symm_apply i, apply H }
def
pgame.right_moves_nim_rec_on
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "ordinal" ]
A recursion principle for right moves of a nim game.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_empty_nim_zero_left_moves : is_empty (nim 0).left_moves
by { rw nim_def, exact ordinal.is_empty_out_zero }
instance
pgame.is_empty_nim_zero_left_moves
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "is_empty", "ordinal.is_empty_out_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_empty_nim_zero_right_moves : is_empty (nim 0).right_moves
by { rw nim_def, exact ordinal.is_empty_out_zero }
instance
pgame.is_empty_nim_zero_right_moves
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "is_empty", "ordinal.is_empty_out_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nim_zero_relabelling : nim 0 ≡r 0
relabelling.is_empty _
def
pgame.nim_zero_relabelling
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[]
`nim 0` has exactly the same moves as `0`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nim_zero_equiv : nim 0 ≈ 0
equiv.is_empty _
theorem
pgame.nim_zero_equiv
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "equiv.is_empty" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unique_nim_one_left_moves : unique (nim 1).left_moves
(equiv.cast $ left_moves_nim 1).unique
instance
pgame.unique_nim_one_left_moves
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "equiv.cast", "unique" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unique_nim_one_right_moves : unique (nim 1).right_moves
(equiv.cast $ right_moves_nim 1).unique
instance
pgame.unique_nim_one_right_moves
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "equiv.cast", "unique" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
default_nim_one_left_moves_eq : (default : (nim 1).left_moves) = @to_left_moves_nim 1 ⟨0, zero_lt_one⟩
rfl
theorem
pgame.default_nim_one_left_moves_eq
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
default_nim_one_right_moves_eq : (default : (nim 1).right_moves) = @to_right_moves_nim 1 ⟨0, zero_lt_one⟩
rfl
theorem
pgame.default_nim_one_right_moves_eq
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_left_moves_nim_one_symm (i) : (@to_left_moves_nim 1).symm i = ⟨0, zero_lt_one⟩
by simp
theorem
pgame.to_left_moves_nim_one_symm
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_right_moves_nim_one_symm (i) : (@to_right_moves_nim 1).symm i = ⟨0, zero_lt_one⟩
by simp
theorem
pgame.to_right_moves_nim_one_symm
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nim_one_move_left (x) : (nim 1).move_left x = nim 0
by simp
theorem
pgame.nim_one_move_left
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nim_one_move_right (x) : (nim 1).move_right x = nim 0
by simp
theorem
pgame.nim_one_move_right
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nim_one_relabelling : nim 1 ≡r star
begin rw nim_def, refine ⟨_, _, λ i, _, λ j, _⟩, any_goals { dsimp, apply equiv.equiv_of_unique }, all_goals { simp, exact nim_zero_relabelling } end
def
pgame.nim_one_relabelling
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "equiv.equiv_of_unique" ]
`nim 1` has exactly the same moves as `star`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nim_one_equiv : nim 1 ≈ star
nim_one_relabelling.equiv
theorem
pgame.nim_one_equiv
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nim_birthday (o : ordinal) : (nim o).birthday = o
begin induction o using ordinal.induction with o IH, rw [nim_def, birthday_def], dsimp, rw max_eq_right le_rfl, convert lsub_typein o, exact funext (λ i, IH _ (typein_lt_self i)) end
lemma
pgame.nim_birthday
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "le_rfl", "ordinal", "ordinal.induction" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
neg_nim (o : ordinal) : -nim o = nim o
begin induction o using ordinal.induction with o IH, rw nim_def, dsimp; congr; funext i; exact IH _ (ordinal.typein_lt_self i) end
lemma
pgame.neg_nim
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "ordinal", "ordinal.induction", "ordinal.typein_lt_self" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nim_impartial (o : ordinal) : impartial (nim o)
begin induction o using ordinal.induction with o IH, rw [impartial_def, neg_nim], refine ⟨equiv_rfl, λ i, _, λ i, _⟩; simpa using IH _ (typein_lt_self _) end
instance
pgame.nim_impartial
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "ordinal", "ordinal.induction" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nim_fuzzy_zero_of_ne_zero {o : ordinal} (ho : o ≠ 0) : nim o ‖ 0
begin rw [impartial.fuzzy_zero_iff_lf, nim_def, lf_zero_le], rw ←ordinal.pos_iff_ne_zero at ho, exact ⟨(ordinal.principal_seg_out ho).top, by simp⟩ end
lemma
pgame.nim_fuzzy_zero_of_ne_zero
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "ordinal", "ordinal.principal_seg_out" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nim_add_equiv_zero_iff (o₁ o₂ : ordinal) : nim o₁ + nim o₂ ≈ 0 ↔ o₁ = o₂
begin split, { refine not_imp_not.1 (λ (hne : _ ≠ _), (impartial.not_equiv_zero_iff _).2 _), wlog h : o₁ < o₂, { exact (fuzzy_congr_left add_comm_equiv).1 (this _ _ hne.symm (hne.lt_or_lt.resolve_left h)) }, rw [impartial.fuzzy_zero_iff_gf, zero_lf_le, nim_def o₂], refine ⟨to_left_moves_add (sum.inr...
lemma
pgame.nim_add_equiv_zero_iff
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "ordinal", "ordinal.principal_seg_out" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nim_add_fuzzy_zero_iff {o₁ o₂ : ordinal} : nim o₁ + nim o₂ ‖ 0 ↔ o₁ ≠ o₂
by rw [iff_not_comm, impartial.not_fuzzy_zero_iff, nim_add_equiv_zero_iff]
lemma
pgame.nim_add_fuzzy_zero_iff
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "iff_not_comm", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nim_equiv_iff_eq {o₁ o₂ : ordinal} : nim o₁ ≈ nim o₂ ↔ o₁ = o₂
by rw [impartial.equiv_iff_add_equiv_zero, nim_add_equiv_zero_iff]
lemma
pgame.nim_equiv_iff_eq
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
grundy_value : Π (G : pgame.{u}), ordinal.{u}
| G := ordinal.mex.{u u} (λ i, grundy_value (G.move_left i)) using_well_founded { dec_tac := pgame_wf_tac }
def
pgame.grundy_value
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[]
The Grundy value of an impartial game, the ordinal which corresponds to the game of nim that the game is equivalent to
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
grundy_value_eq_mex_left (G : pgame) : grundy_value G = ordinal.mex.{u u} (λ i, grundy_value (G.move_left i))
by rw grundy_value
lemma
pgame.grundy_value_eq_mex_left
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv_nim_grundy_value : ∀ (G : pgame.{u}) [G.impartial], G ≈ nim (grundy_value G)
| G := begin introI hG, rw [impartial.equiv_iff_add_equiv_zero, ←impartial.forall_left_moves_fuzzy_iff_equiv_zero], intro i, apply left_moves_add_cases i, { intro i₁, rw add_move_left_inl, apply (fuzzy_congr_left (add_congr_left (equiv_nim_grundy_value (G.move_left i₁)).symm)).1, rw nim_add_fuzzy_...
theorem
pgame.equiv_nim_grundy_value
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "cInf_le'", "ordinal.ne_mex", "ordinal.typein", "ordinal.typein_lt_self", "quotient.out" ]
The Sprague-Grundy theorem which states that every impartial game is equivalent to a game of nim, namely the game of nim corresponding to the games Grundy value
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
grundy_value_eq_iff_equiv_nim {G : pgame} [G.impartial] {o : ordinal} : grundy_value G = o ↔ G ≈ nim o
⟨by { rintro rfl, exact equiv_nim_grundy_value G }, by { intro h, rw ←nim_equiv_iff_eq, exact (equiv_nim_grundy_value G).symm.trans h }⟩
lemma
pgame.grundy_value_eq_iff_equiv_nim
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "ordinal", "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nim_grundy_value (o : ordinal.{u}) : grundy_value (nim o) = o
grundy_value_eq_iff_equiv_nim.2 pgame.equiv_rfl
lemma
pgame.nim_grundy_value
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "pgame.equiv_rfl" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
grundy_value_eq_iff_equiv (G H : pgame) [G.impartial] [H.impartial] : grundy_value G = grundy_value H ↔ G ≈ H
grundy_value_eq_iff_equiv_nim.trans (equiv_congr_left.1 (equiv_nim_grundy_value H) _).symm
lemma
pgame.grundy_value_eq_iff_equiv
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
grundy_value_zero : grundy_value 0 = 0
grundy_value_eq_iff_equiv_nim.2 nim_zero_equiv.symm
lemma
pgame.grundy_value_zero
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
grundy_value_iff_equiv_zero (G : pgame) [G.impartial] : grundy_value G = 0 ↔ G ≈ 0
by rw [←grundy_value_eq_iff_equiv, grundy_value_zero]
lemma
pgame.grundy_value_iff_equiv_zero
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
grundy_value_star : grundy_value star = 1
grundy_value_eq_iff_equiv_nim.2 nim_one_equiv.symm
lemma
pgame.grundy_value_star
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
grundy_value_neg (G : pgame) [G.impartial] : grundy_value (-G) = grundy_value G
by rw [grundy_value_eq_iff_equiv_nim, neg_equiv_iff, neg_nim, ←grundy_value_eq_iff_equiv_nim]
lemma
pgame.grundy_value_neg
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
grundy_value_eq_mex_right : ∀ (G : pgame) [G.impartial], grundy_value G = ordinal.mex.{u u} (λ i, grundy_value (G.move_right i))
| ⟨l, r, L, R⟩ := begin introI H, rw [←grundy_value_neg, grundy_value_eq_mex_left], congr, ext i, haveI : (R i).impartial := @impartial.move_right_impartial ⟨l, r, L, R⟩ _ i, apply grundy_value_neg end
lemma
pgame.grundy_value_eq_mex_right
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
grundy_value_nim_add_nim (n m : ℕ) : grundy_value (nim.{u} n + nim.{u} m) = nat.lxor n m
begin -- We do strong induction on both variables. induction n using nat.strong_induction_on with n hn generalizing m, induction m using nat.strong_induction_on with m hm, rw grundy_value_eq_mex_left, apply (ordinal.mex_le_of_ne.{u u} (λ i, _)).antisymm (ordinal.le_mex_of_forall (λ ou hu, _)), -- The Grundy...
lemma
pgame.grundy_value_nim_add_nim
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "equiv.symm_apply_apply", "nat.lt_lxor_cases", "nat.lxor_cancel_left", "nat.lxor_cancel_right", "nat.lxor_comm", "nat.lxor_left_inj", "nat.lxor_right_inj", "ordinal.le_mex_of_forall", "ordinal.nat_cast_inj", "ordinal.nat_lt_omega" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nim_add_nim_equiv {n m : ℕ} : nim n + nim m ≈ nim (nat.lxor n m)
by rw [←grundy_value_eq_iff_equiv_nim, grundy_value_nim_add_nim]
lemma
pgame.nim_add_nim_equiv
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
grundy_value_add (G H : pgame) [G.impartial] [H.impartial] {n m : ℕ} (hG : grundy_value G = n) (hH : grundy_value H = m) : grundy_value (G + H) = nat.lxor n m
begin rw [←nim_grundy_value (nat.lxor n m), grundy_value_eq_iff_equiv], refine equiv.trans _ nim_add_nim_equiv, convert add_congr (equiv_nim_grundy_value G) (equiv_nim_grundy_value H); simp only [hG, hH] end
lemma
pgame.grundy_value_add
set_theory.game
src/set_theory/game/nim.lean
[ "data.nat.bitwise", "set_theory.game.birthday", "set_theory.game.impartial" ]
[ "equiv.trans", "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_def (o : ordinal) : o.to_pgame = ⟨o.out.α, pempty, λ x, (typein (<) x).to_pgame, pempty.elim⟩
by rw to_pgame
theorem
ordinal.to_pgame_def
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "ordinal", "pempty" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_left_moves (o : ordinal) : o.to_pgame.left_moves = o.out.α
by rw [to_pgame, left_moves]
theorem
ordinal.to_pgame_left_moves
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_right_moves (o : ordinal) : o.to_pgame.right_moves = pempty
by rw [to_pgame, right_moves]
theorem
ordinal.to_pgame_right_moves
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "ordinal", "pempty" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_empty_zero_to_pgame_left_moves : is_empty (to_pgame 0).left_moves
by { rw to_pgame_left_moves, apply_instance }
instance
ordinal.is_empty_zero_to_pgame_left_moves
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "is_empty" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_empty_to_pgame_right_moves (o : ordinal) : is_empty o.to_pgame.right_moves
by { rw to_pgame_right_moves, apply_instance }
instance
ordinal.is_empty_to_pgame_right_moves
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "is_empty", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_left_moves_to_pgame {o : ordinal} : set.Iio o ≃ o.to_pgame.left_moves
(enum_iso_out o).to_equiv.trans (equiv.cast (to_pgame_left_moves o).symm)
def
ordinal.to_left_moves_to_pgame
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "equiv.cast", "ordinal", "set.Iio" ]
Converts an ordinal less than `o` into a move for the `pgame` corresponding to `o`, and vice versa.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_left_moves_to_pgame_symm_lt {o : ordinal} (i : o.to_pgame.left_moves) : ↑(to_left_moves_to_pgame.symm i) < o
(to_left_moves_to_pgame.symm i).prop
theorem
ordinal.to_left_moves_to_pgame_symm_lt
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_move_left_heq {o : ordinal} : o.to_pgame.move_left == λ x : o.out.α, (typein (<) x).to_pgame
by { rw to_pgame, refl }
theorem
ordinal.to_pgame_move_left_heq
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_move_left' {o : ordinal} (i) : o.to_pgame.move_left i = (to_left_moves_to_pgame.symm i).val.to_pgame
(congr_heq to_pgame_move_left_heq.symm (cast_heq _ i)).symm
theorem
ordinal.to_pgame_move_left'
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "congr_heq", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_move_left {o : ordinal} (i) : o.to_pgame.move_left (to_left_moves_to_pgame i) = i.val.to_pgame
by simp
theorem
ordinal.to_pgame_move_left
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
zero_to_pgame_relabelling : to_pgame 0 ≡r 0
relabelling.is_empty _
def
ordinal.zero_to_pgame_relabelling
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[]
`0.to_pgame` has the same moves as `0`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unique_one_to_pgame_left_moves : unique (to_pgame 1).left_moves
(equiv.cast $ to_pgame_left_moves 1).unique
instance
ordinal.unique_one_to_pgame_left_moves
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "equiv.cast", "unique" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_to_pgame_left_moves_default_eq : (default : (to_pgame 1).left_moves) = @to_left_moves_to_pgame 1 ⟨0, zero_lt_one⟩
rfl
theorem
ordinal.one_to_pgame_left_moves_default_eq
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_left_moves_one_to_pgame_symm (i) : (@to_left_moves_to_pgame 1).symm i = ⟨0, zero_lt_one⟩
by simp
theorem
ordinal.to_left_moves_one_to_pgame_symm
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_to_pgame_move_left (x) : (to_pgame 1).move_left x = to_pgame 0
by simp
theorem
ordinal.one_to_pgame_move_left
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_to_pgame_relabelling : to_pgame 1 ≡r 1
⟨equiv.equiv_of_unique _ _, equiv.equiv_of_is_empty _ _, λ i, by simpa using zero_to_pgame_relabelling, is_empty_elim⟩
def
ordinal.one_to_pgame_relabelling
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "equiv.equiv_of_is_empty" ]
`1.to_pgame` has the same moves as `1`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_lf {a b : ordinal} (h : a < b) : a.to_pgame ⧏ b.to_pgame
by { convert move_left_lf (to_left_moves_to_pgame ⟨a, h⟩), rw to_pgame_move_left }
theorem
ordinal.to_pgame_lf
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_le {a b : ordinal} (h : a ≤ b) : a.to_pgame ≤ b.to_pgame
begin refine le_iff_forall_lf.2 ⟨λ i, _, is_empty_elim⟩, rw to_pgame_move_left', exact to_pgame_lf ((to_left_moves_to_pgame_symm_lt i).trans_le h) end
theorem
ordinal.to_pgame_le
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_lt {a b : ordinal} (h : a < b) : a.to_pgame < b.to_pgame
⟨to_pgame_le h.le, to_pgame_lf h⟩
theorem
ordinal.to_pgame_lt
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_nonneg (a : ordinal) : 0 ≤ a.to_pgame
zero_to_pgame_relabelling.ge.trans $ to_pgame_le $ ordinal.zero_le a
theorem
ordinal.to_pgame_nonneg
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "ordinal", "ordinal.zero_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_lf_iff {a b : ordinal} : a.to_pgame ⧏ b.to_pgame ↔ a < b
⟨by { contrapose, rw [not_lt, not_lf], exact to_pgame_le }, to_pgame_lf⟩
theorem
ordinal.to_pgame_lf_iff
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_le_iff {a b : ordinal} : a.to_pgame ≤ b.to_pgame ↔ a ≤ b
⟨by { contrapose, rw [not_le, pgame.not_le], exact to_pgame_lf }, to_pgame_le⟩
theorem
ordinal.to_pgame_le_iff
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "ordinal", "pgame.not_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_lt_iff {a b : ordinal} : a.to_pgame < b.to_pgame ↔ a < b
⟨by { contrapose, rw not_lt, exact λ h, not_lt_of_le (to_pgame_le h) }, to_pgame_lt⟩
theorem
ordinal.to_pgame_lt_iff
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "not_lt_of_le", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_equiv_iff {a b : ordinal} : a.to_pgame ≈ b.to_pgame ↔ a = b
by rw [pgame.equiv, le_antisymm_iff, to_pgame_le_iff, to_pgame_le_iff]
theorem
ordinal.to_pgame_equiv_iff
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "ordinal", "pgame.equiv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_injective : function.injective ordinal.to_pgame
λ a b h, to_pgame_equiv_iff.1 $ equiv_of_eq h
theorem
ordinal.to_pgame_injective
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_eq_iff {a b : ordinal} : a.to_pgame = b.to_pgame ↔ a = b
to_pgame_injective.eq_iff
theorem
ordinal.to_pgame_eq_iff
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_embedding : ordinal.{u} ↪o pgame.{u}
{ to_fun := ordinal.to_pgame, inj' := to_pgame_injective, map_rel_iff' := @to_pgame_le_iff }
def
ordinal.to_pgame_embedding
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[]
The order embedding version of `to_pgame`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_add : ∀ a b : ordinal.{u}, a.to_pgame + b.to_pgame ≈ (a ♯ b).to_pgame
| a b := begin refine ⟨le_of_forall_lf (λ i, _) is_empty_elim, le_of_forall_lf (λ i, _) is_empty_elim⟩, { apply left_moves_add_cases i; intro i; let wf := to_left_moves_to_pgame_symm_lt i; try { rw add_move_left_inl }; try { rw add_move_left_inr }; rw [to_pgame_move_left', lf_congr_left (to_pgame_ad...
theorem
ordinal.to_pgame_add
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "is_empty_elim" ]
The sum of ordinals as games corresponds to natural addition of ordinals.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pgame_add_mk (a b : ordinal) : ⟦a.to_pgame⟧ + ⟦b.to_pgame⟧ = ⟦(a ♯ b).to_pgame⟧
quot.sound (to_pgame_add a b)
theorem
ordinal.to_pgame_add_mk
set_theory.game
src/set_theory/game/ordinal.lean
[ "set_theory.game.basic", "set_theory.ordinal.natural_ops" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pgame : Type (u+1) | mk : ∀ α β : Type u, (α → pgame) → (β → pgame) → pgame
inductive
pgame
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[]
The type of pre-games, before we have quotiented by equivalence (`pgame.setoid`). In ZFC, a combinatorial game is constructed from two sets of combinatorial games that have been constructed at an earlier stage. To do this in type theory, we say that a pre-game is built inductively from two families of pre-games...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
left_moves : pgame → Type u
| (mk l _ _ _) := l
def
pgame.left_moves
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
The indexing type for allowable moves by Left.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
right_moves : pgame → Type u
| (mk _ r _ _) := r
def
pgame.right_moves
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
The indexing type for allowable moves by Right.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
move_left : Π (g : pgame), left_moves g → pgame
| (mk l _ L _) := L
def
pgame.move_left
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
The new game after Left makes an allowed move.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
move_right : Π (g : pgame), right_moves g → pgame
| (mk _ r _ R) := R
def
pgame.move_right
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
The new game after Right makes an allowed move.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
left_moves_mk {xl xr xL xR} : (⟨xl, xr, xL, xR⟩ : pgame).left_moves = xl
rfl
lemma
pgame.left_moves_mk
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
move_left_mk {xl xr xL xR} : (⟨xl, xr, xL, xR⟩ : pgame).move_left = xL
rfl
lemma
pgame.move_left_mk
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
right_moves_mk {xl xr xL xR} : (⟨xl, xr, xL, xR⟩ : pgame).right_moves = xr
rfl
lemma
pgame.right_moves_mk
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
move_right_mk {xl xr xL xR} : (⟨xl, xr, xL, xR⟩ : pgame).move_right = xR
rfl
lemma
pgame.move_right_mk
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_lists (L R : list pgame.{u}) : pgame.{u}
mk (ulift (fin L.length)) (ulift (fin R.length)) (λ i, L.nth_le i.down i.down.is_lt) (λ j, R.nth_le j.down j.down.prop)
def
pgame.of_lists
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
left_moves_of_lists (L R : list pgame) : (of_lists L R).left_moves = ulift (fin L.length)
rfl
lemma
pgame.left_moves_of_lists
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
right_moves_of_lists (L R : list pgame) : (of_lists L R).right_moves = ulift (fin R.length)
rfl
lemma
pgame.right_moves_of_lists
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_of_lists_left_moves {L R : list pgame} : fin L.length ≃ (of_lists L R).left_moves
((equiv.cast (left_moves_of_lists L R).symm).trans equiv.ulift).symm
def
pgame.to_of_lists_left_moves
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "equiv.cast", "equiv.ulift", "pgame" ]
Converts a number into a left move for `of_lists`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_of_lists_right_moves {L R : list pgame} : fin R.length ≃ (of_lists L R).right_moves
((equiv.cast (right_moves_of_lists L R).symm).trans equiv.ulift).symm
def
pgame.to_of_lists_right_moves
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "equiv.cast", "equiv.ulift", "pgame" ]
Converts a number into a right move for `of_lists`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_lists_move_left {L R : list pgame} (i : fin L.length) : (of_lists L R).move_left (to_of_lists_left_moves i) = L.nth_le i i.is_lt
rfl
theorem
pgame.of_lists_move_left
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_lists_move_left' {L R : list pgame} (i : (of_lists L R).left_moves) : (of_lists L R).move_left i = L.nth_le (to_of_lists_left_moves.symm i) (to_of_lists_left_moves.symm i).is_lt
rfl
theorem
pgame.of_lists_move_left'
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_lists_move_right {L R : list pgame} (i : fin R.length) : (of_lists L R).move_right (to_of_lists_right_moves i) = R.nth_le i i.is_lt
rfl
theorem
pgame.of_lists_move_right
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_lists_move_right' {L R : list pgame} (i : (of_lists L R).right_moves) : (of_lists L R).move_right i = R.nth_le (to_of_lists_right_moves.symm i) (to_of_lists_right_moves.symm i).is_lt
rfl
theorem
pgame.of_lists_move_right'
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
move_rec_on {C : pgame → Sort*} (x : pgame) (IH : ∀ (y : pgame), (∀ i, C (y.move_left i)) → (∀ j, C (y.move_right j)) → C y) : C x
x.rec_on $ λ yl yr yL yR, IH (mk yl yr yL yR)
def
pgame.move_rec_on
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
A variant of `pgame.rec_on` expressed in terms of `pgame.move_left` and `pgame.move_right`. Both this and `pgame.rec_on` describe Conway induction on games.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_option : pgame → pgame → Prop | move_left {x : pgame} (i : x.left_moves) : is_option (x.move_left i) x | move_right {x : pgame} (i : x.right_moves) : is_option (x.move_right i) x
inductive
pgame.is_option
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
`is_option x y` means that `x` is either a left or right option for `y`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_option.mk_left {xl xr : Type u} (xL : xl → pgame) (xR : xr → pgame) (i : xl) : (xL i).is_option (mk xl xr xL xR)
@is_option.move_left (mk _ _ _ _) i
theorem
pgame.is_option.mk_left
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_option.mk_right {xl xr : Type u} (xL : xl → pgame) (xR : xr → pgame) (i : xr) : (xR i).is_option (mk xl xr xL xR)
@is_option.move_right (mk _ _ _ _) i
theorem
pgame.is_option.mk_right
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
wf_is_option : well_founded is_option
⟨λ x, move_rec_on x $ λ x IHl IHr, acc.intro x $ λ y h, begin induction h with _ i _ j, { exact IHl i }, { exact IHr j } end⟩
theorem
pgame.wf_is_option
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subsequent : pgame → pgame → Prop
trans_gen is_option
def
pgame.subsequent
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[ "pgame" ]
`subsequent x y` says that `x` can be obtained by playing some nonempty sequence of moves from `y`. It is the transitive closure of `is_option`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subsequent.trans {x y z} : subsequent x y → subsequent y z → subsequent x z
trans_gen.trans
theorem
pgame.subsequent.trans
set_theory.game
src/set_theory/game/pgame.lean
[ "data.fin.basic", "data.list.basic", "logic.relation", "logic.small.basic", "order.game_add" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83