(** The same holds with weak excluded middle. The proof is a little more involved, however. *)
Section Weak_proof_irrelevance_CCI.
Hypothesis wem : forall A:Prop, ~~A \/ ~ A.

Theorem wem_proof_irrelevance_cci : forall (B:Prop) (b1 b2:B), ~~b1 = b2.
End Weak_proof_irrelevance_CCI.