Theorem: Etch.Verification.Stream.index'_invalid (Etch/StreamFusion/Proofs/StreamProof.lean)

State before:
ι : Type
α : Type u_1
a b s : Stream ι α
x : s.σ
h : s.valid x = false
⊢ ¬s.valid x = true
Tactic:
simpa
State after:
no goals