∀ {α : Type} {ref : IO.Ref α} {mutex : Std.BaseRecursiveMutex} {ref_1 : IO.Ref α} {mutex_1 : Std.BaseRecursiveMutex},
  { ref := ref, mutex := mutex } = { ref := ref_1, mutex := mutex_1 } → ref = ref_1 ∧ mutex = mutex_1