Set: pp::colors
  Set: pp::unicode
Failed to solve
A : (Type U), A' : (Type U), H : A == A' ⊢ ?M::3 ≺ TypeU
    (line: 1: pos: 44) Type of argument 1 must be convertible to the expected type in the application of
        @symm
    with arguments:
        ?M::0
        A
        A'
        H