theorem extracted_formal_statement_4 : |1| = 1 := sorry

State before:
case inr
n : ℕ
σ : Signs n
k : Fin n
this : ↑(σ k) ∈ {-1, 1}
h : ↑(σ k) = 1
⊢ |1| = 1

Tactic: simp

State after:

Relevant lemmas: