theorem extracted_formal_statement_1 : |(-1)| = 1 := sorry

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

Tactic: rw [h]

State after:
[case inl
 n : ℕ
 σ : Signs n
 k : Fin n
 this : ↑(σ k) ∈ {-1, 1}
 h : ↑(σ k) = -1
 ⊢ |(-1)| = 1]

Relevant lemmas: