Goal:
    A : Type  RA : ReflectEq A  x : list A
  ============================
   (forall y : list A, reflectProp (x = y) (eqb_list eqb x y))


DEBUG:Going to execute:
let H := fresh x in
           intro
           H
Level 2: Backtrace:

The first hypothesis in the goal is not an equality.
Level 2: Backtrace:

The first hypothesis in the goal is not an equality.
Level 2: Backtrace:

The first hypothesis in the goal is not an equality.
Level 2: Backtrace:

The first hypothesis in the goal is not an equality.