theorem extracted_formal_statement_72.{u_4} {E : Type u_4} [inst : NormedAddCommGroup E] {a : E} {s : Set E} (h : -a ∈ s) :
  -a ∈ s := sorry

State before:
E : Type u_4
inst✝ : NormedAddCommGroup E
a : E
s : Set E
h : -a ∈ s
⊢ -a ∈ s

Tactic: exact h

State after:

Relevant lemmas: