pith. machine review for the scientific record. sign in
theorem

FApply_sub

proved
show as:
view math explainer →
module
IndisputableMonolith.Cost.Ndim.Projector
domain
Cost
line
207 · github
papers citing
none yet

open explainer

Generate a durable explainer page for this declaration.

open lean source

IndisputableMonolith.Cost.Ndim.Projector on GitHub at line 207.

browse module

All declarations in this module, on Recognition.

explainer page

Tracked in the explainer inventory; generation is lazy so crawlers do not trigger LLM jobs.

open explainer

depends on

formal source

 204    FApply lam hInv β (-w) = -FApply lam hInv β w := by
 205  simpa using FApply_smul lam hInv β (-1) w
 206
 207theorem FApply_sub {n : ℕ}
 208    (lam : ℝ) (hInv : Fin n → Fin n → ℝ) (β : Vec n)
 209    (v w : Vec n) :
 210    FApply lam hInv β (v - w) = FApply lam hInv β v - FApply lam hInv β w := by
 211  ext i
 212  simp [sub_eq_add_neg, FApply_add, FApply_neg]
 213
 214theorem FApply_square {n : ℕ}
 215    (lam : ℝ) (hInv : Fin n → Fin n → ℝ) (β : Vec n)
 216    (hμ : mu lam hInv β ≠ 0) (v : Vec n) :
 217    FApply lam hInv β (FApply lam hInv β v) = v := by
 218  ext i
 219  have hPFi : PApply lam hInv β (FApply lam hInv β v) i = PApply lam hInv β v i := by
 220    simpa using congrFun (PApply_FApply lam hInv β hμ v) i
 221  calc
 222    FApply lam hInv β (FApply lam hInv β v) i
 223        = (2 • PApply lam hInv β (FApply lam hInv β v) - FApply lam hInv β v) i := by
 224            simp [FApply]
 225    _ = (2 • PApply lam hInv β v - FApply lam hInv β v) i := by
 226          simp [hPFi]
 227    _ = v i := by
 228          simp [FApply]
 229
 230theorem FApply_GApply {n : ℕ}
 231    (lam : ℝ) (hInv : Fin n → Fin n → ℝ) (β : Vec n)
 232    (hμ : mu lam hInv β ≠ 0) (v : Vec n) :
 233    FApply lam hInv β (GApply lam hInv β v)
 234      = ((1 : ℝ) / 2) • FApply lam hInv β v + (Real.sqrt 5 / 2) • v := by
 235  unfold GApply
 236  rw [FApply_add, FApply_smul, FApply_smul, FApply_square _ _ _ hμ]
 237