apply KVChain.eq_of_toList_eq
α : Type u
r : α → α → Prop
inst✝¹ : StrictLinearOrder r
inst✝ : DecidableRel r
β : α → Type v
f : (a : α) → β a → β a → Option (β a)
xs : KVChain r β
a : α
b : β a
ys : KVChain r β
hays : boundLeft a ys
haxs : boundLeft a xs
⊢ mergeWith f xs (KVChain.cons a b ys hays) = KVChain.cons a b (mergeWith f xs ys) (_ : boundLeft a (mergeWith f xs ys))
case a
α : Type u
r : α → α → Prop
inst✝¹ : StrictLinearOrder r
inst✝ : DecidableRel r
β : α → Type v
f : (a : α) → β a → β a → Option (β a)
xs : KVChain r β
a : α
b : β a
ys : KVChain r β
hays : boundLeft a ys
haxs : boundLeft a xs
⊢ (mergeWith f xs (KVChain.cons a b ys hays)).toList =
    (KVChain.cons a b (mergeWith f xs ys) (_ : boundLeft a (mergeWith f xs ys))).toList