openAI-math-dataset / lean /OAI /Combinatorics /BinaryEdit /FiniteVectorRestrictions.lean
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Add lean source and binary files (part 40)
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import OAI.Combinatorics.BinaryEdit.FiniteVectors
namespace OAI
/-! Coordinate restrictions of the finite subtree vectors. -/
namespace TreeEdit.BinaryLower.FiniteVectors
variable {m k : ℕ}
/-- On a child's subtree the parent's cheap vector equals that child's
distinguished vector. -/
theorem u_on_child (p : Fin k → Fin m → ℕ) (j : ℕ) (hj : j < k)
(a b : Leaf m k) (i : Fin m)
(hab : Agrees (j + 1) (Function.update a ⟨j, hj⟩ i) b) :
u p j a b = w p (j + 1) (Function.update a ⟨j, hj⟩ i) b := by
have hp := ((agrees_child_iff j hj a b i).1 hab).1
simp [u, w, hp, hab]
/-- The parent's distinguished vector restricts to `R` times the child's. -/
theorem w_on_child (p : Fin k → Fin m → ℕ) (j : ℕ) (hj : j < k)
(a b : Leaf m k) (i : Fin m)
(hab : Agrees (j + 1) (Function.update a ⟨j, hj⟩ i) b) :
w p j a b = levelProduct p ⟨j, hj⟩ •
w p (j + 1) (Function.update a ⟨j, hj⟩ i) b := by
have h := congrFun (w_eq_level_nsmul_u p j hj a) b
simpa [u_on_child p j hj a b i hab] using h
@[simp] theorem u_off_subtree (p : Fin k → Fin m → ℕ) (j : ℕ)
(a b : Leaf m k) (hab : ¬ Agrees j a b) : u p j a b = 0 := by
simp [u, hab]
@[simp] theorem w_off_subtree (p : Fin k → Fin m → ℕ) (j : ℕ)
(a b : Leaf m k) (hab : ¬ Agrees j a b) : w p j a b = 0 := by
simp [w, hab]
/-- A leaf coordinate outside a subtree is fixed by every integer multiple
of its cheap vector. -/
theorem translate_u_off_subtree (p : Fin k → Fin m → ℕ) (j : ℕ)
(a b : Leaf m k) (hab : ¬ Agrees j a b) (x : State p) (t : ℤ) :
(x + t • u p j a) b = x b := by
simp [u, hab]
/-- The same support statement for the distinguished vector. -/
theorem translate_w_off_subtree (p : Fin k → Fin m → ℕ) (j : ℕ)
(a b : Leaf m k) (hab : ¬ Agrees j a b) (x : State p) (t : ℤ) :
(x + t • w p j a) b = x b := by
simp [w, hab]
end TreeEdit.BinaryLower.FiniteVectors
end OAI