Theorems · Theorem · ring theory

DirectSum.coe_mul_of_apply_aux

∀ {ι : Type u_1} {σ : Type u_2} {R : Type u_4} [inst : DecidableEq ι] [inst_1 : Semiring R] [inst_2 : SetLike σ R]
  [inst_3 : AddSubmonoidClass σ R] (A : ι → σ) [inst_4 : AddMonoid ι] [inst_5 : SetLike.GradedMonoid A]
  (r : DirectSum ι fun i => ↥(A i)) {i : ι} (r' : ↥(A i)) {j n : ι},
  (∀ (x : ι), x + i = n ↔ x = j) → ↑((r * (DirectSum.of (fun i => ↥(A i)) i) r') n) = ↑(r j) * ↑r'

Defined in

Mathlib.Algebra.DirectSum.Internal

Cited by

3 results in Mathlib

Foundations

Depth 89 from the axioms · uses propext, Classical.choice, Quot.sound

Assumes

DecidableEqSemiringSetLikeAddSubmonoidClassAddMonoidSetLike.GradedMonoid