case nil => simp [<-Word.eps_eq_nil, Word.monoid.mul_one]; rfl
α✝ : Type ?u.20791
L✝ : Language α✝
u v : Word α✝
α : Type
Z : Finset α
L : Language { x // x ∈ Z }
proc : DecisionProcedure L
nc✝ nc : Fintype (Quotient (myhillNerodeEquivalence L))
w : Word { x // x ∈ (canonicalAutomaton nc).Z }
⊢ ↑(TotalDFA.del_star' (canonicalAutomaton nc) ({ val := ⟦w⟧, property := ⋯ }, [])) =
    ↑{ val := ⟦w * []⟧, property := ⋯ }
no goals