Set: pp::colors
  Set: pp::unicode
  Set: lean::pp::implicit
  Set: lean::pp::coercion
  Set: lean::pp::notation
  Assumed: vector
  Assumed: read
  Assumed: V1
  Defined: D
Definition D : ℤ := @read ℤ 10 V1 1 Trivial
  Assumed: b
  Defined: a
  Proved: T