simp at *
case h_2
n : ℕ
v₁ v₂ : Variables n order.Lex
m : ℕ
a b : Vector ℕ m
p q : List.length [] = m
v₁✝ v₂✝ : Vector ℕ m
x✝ : ℕ
tail✝¹ : List ℕ
property✝¹ : List.length (x✝ :: tail✝¹) = m
y✝ : ℕ
tail✝ : List ℕ
property✝ : List.length (y✝ :: tail✝) = m
heq✝¹ : { val := [], property := p } = { val := x✝ :: tail✝¹, property := property✝¹ }
heq✝ : { val := [], property := q } = { val := y✝ :: tail✝, property := property✝ }
⊢ (if x✝ = y✝ then Order.lex_impl (tail { val := [], property := p }) (tail { val := [], property := q })
    else x✝ ≤ y✝) ∨
    if x✝ = y✝ then Order.lex_impl (tail { val := [], property := p }) (tail { val := [], property := q }) else x✝ ≤ y✝
no goals