Goal:
    A : Type  R : ReflectEq A  x : A  y : A  Heq_anonymous : true = (x == y)
  ============================
   (x = y)


DEBUG:Going to execute:
intro
Level 2: Backtrace:

The goal is not a product.
Level 2: Backtrace:

The goal is not a product.
Level 2: Backtrace:

The goal is not a product.
Level 2: Backtrace:

The goal is not a product.