simp [h]
case pos
R G : Type
inst✝² : Ring R
inst✝¹ : Group G
inst✝ : DecidableEq G
p : FormalSum R G
x : G
hyp :
  (fun x => FreeModule.coordinates x (Quotient.mk (formalSumSetoid R G) p) ≠ 0) x ∧
    ∀ (y : G), (fun x => FreeModule.coordinates x (Quotient.mk (formalSumSetoid R G) p) ≠ 0) y → y = x
hyp₁ : (fun x => FreeModule.coordinates x (Quotient.mk (formalSumSetoid R G) p) ≠ 0) x
hyp₂ : ∀ (y : G), FreeModule.coordinates y (Quotient.mk (formalSumSetoid R G) p) ≠ 0 → y = x
x₁ : G
h : x = x₁
⊢ FormalSum.coords p x₁ =
    match x == x₁ with
    | true => FormalSum.coords p x
    | false => 0
no goals