simp at a2_right
α : Type
inst✝ : DecidableEq α
σ_0 σ_1 : Type
M_0 : EpsilonNFA α σ_0
M_1 : EpsilonNFA α σ_1
c : α
p0 q0 : σ_1
xs : List (σ_0 ⊕ σ_1)
x : SymbolArrow α σ_1
a3_left : x ∈ M_1.symbol_arrow_list
a3_right_left : x.start_state = p0
a3_right_right_left : x.symbol = c
a2_right : Sum.inr q0 ∈ List.map Sum.inr x.stop_state_list
⊢ ∃ stop_state_list,
    { start_state := x.start_state, symbol := x.symbol, stop_state_list := stop_state_list } ∈ M_1.symbol_arrow_list ∧
      q0 ∈ stop_state_list
α : Type
inst✝ : DecidableEq α
σ_0 σ_1 : Type
M_0 : EpsilonNFA α σ_0
M_1 : EpsilonNFA α σ_1
c : α
p0 q0 : σ_1
xs : List (σ_0 ⊕ σ_1)
x : SymbolArrow α σ_1
a3_left : x ∈ M_1.symbol_arrow_list
a3_right_left : x.start_state = p0
a3_right_right_left : x.symbol = c
a2_right : q0 ∈ x.stop_state_list
⊢ ∃ stop_state_list,
    { start_state := x.start_state, symbol := x.symbol, stop_state_list := stop_state_list } ∈ M_1.symbol_arrow_list ∧
      q0 ∈ stop_state_list