exact εClosure.step step' (ih step)
case step
j i k : ℕ
nfa : NFA
i✝ j✝ k✝ : ℕ
step' : j✝ ∈ nfa.εStep i✝
rest✝ : nfa.εClosure j✝ k✝
ih : k ∈ nfa.εStep k✝ → k ∈ nfa.εClosure j✝
step : k ∈ nfa.εStep k✝
⊢ k ∈ nfa.εClosure i✝
no goals