`BookProof.ChapterAbelianDiagonalCountable.diagOp_coordUnit_apply` (i : ℕ) (f : Ell2C) (j : ℕ) : ((diagOp (coordUnit i) f : Ell2C) : ℕ → ℂ) j = if j = i then (f : ℕ → ℂ) i else 0
ProvedBookProof.ChapterAbelianDiagonalCountable.diagOp_coordUnit_applytheoremstimepiece
Prove the following Lean 4 theorem from ChapterAbelianDiagonalCountable.
BookProof.ChapterAbelianDiagonalCountable.diagOp_coordUnit_apply (i : ℕ) (f : Ell2C) (j : ℕ) : ((diagOp (coordUnit i) f : Ell2C) : ℕ → ℂ) j = if j = i then (f : ℕ → ℂ) i else 0
Formalization note: Lean 4 identifier BookProof.ChapterAbelianDiagonalCountable.diagOp_coordUnit_apply.
Preamble
-- Generated from ChapterAbelianDiagonalCountable.lean — theorem BookProof.ChapterAbelianDiagonalCountable.diagOp_coordUnit_apply import Mathlib import Definitions.Def_ChapterAbelianDiagonalCountable open BookProof.ChapterAbelianDiagonalCountable open scoped ENNReal noncomputable section
Formal statement
theorem BookProof.ChapterAbelianDiagonalCountable.diagOp_coordUnit_apply (i : ℕ) (f : Ell2C) (j : ℕ) :
((diagOp (coordUnit i) f : Ell2C) : ℕ → ℂ) j = if j = i then (f : ℕ → ℂ) i else 0 := by sorry