∀ {α : Type u} {β : α → Type v} [inst : BEq α] [inst_1 : LawfulBEq α] {l : List ((a : α) × β a)} {a k : α} {v : β k},
  Std.Internal.List.getValueCast? a (Std.Internal.List.replaceEntry k v l) =
    if h : Std.Internal.List.containsKey k l = true ∧ (k == a) = true then some (cast ⋯ v)
    else Std.Internal.List.getValueCast? a l