Theorem: Matrix.comp₁ (Logic/Vorspiel/Vorspiel.lean)

State before:
n : ℕ
α : Type u
δ✝ : Type u_1
f : α → δ✝
a : α
⊢ f ∘ ![a] = ![f a]
Tactic:
simp[comp_vecCons'']
State after:
no goals