rw [hxeq]
case inr.inl
κ : Type u_1
ν : Type u_2
inst✝ : DecidableEq κ
ys✝ : List (κ × ν)
x k : κ
h : ¬x = k
k' : κ
v : ν
ys : List (κ × ν)
hx : x ∈ map Prod.fst ((k', v) :: ys)
h_term : length (matchKey ys k).snd < Nat.succ (length ys)
h_term' : length ys < Nat.succ (length ys)
hkneq : ¬k' = k
hxeq : x = k'
⊢ x ∈ k' :: map Prod.fst (groupByKey (matchKey (matchKey ys k).snd k').snd)
case inr.inl
κ : Type u_1
ν : Type u_2
inst✝ : DecidableEq κ
ys✝ : List (κ × ν)
x k : κ
h : ¬x = k
k' : κ
v : ν
ys : List (κ × ν)
hx : x ∈ map Prod.fst ((k', v) :: ys)
h_term : length (matchKey ys k).snd < Nat.succ (length ys)
h_term' : length ys < Nat.succ (length ys)
hkneq : ¬k' = k
hxeq : x = k'
⊢ k' ∈ k' :: map Prod.fst (groupByKey (matchKey (matchKey ys k).snd k').snd)