Goal:
    x : t  y : t  Heq_anonymous : false = eqb x y
  ============================
   (x <> y)


DEBUG:Going to execute:
match H with
           | H' => fail 2
           | _ => unify X Y; clear H' || clear H
           end
Level 4: Backtrace:

In environment
x, y : t
Heq_anonymous : false = eqb x y
Unable to unify "t" with "false = eqb x y".
Level 4: Backtrace:

In environment
x, y : t
Heq_anonymous : false = eqb x y
Unable to unify "t" with "false = eqb x y".
Level 4: Backtrace:

In environment
x, y : t
Heq_anonymous : false = eqb x y
Unable to unify "t" with "false = eqb x y".
Level 4: Backtrace:

In environment
x, y : t
Heq_anonymous : false = eqb x y
Unable to unify "t" with "false = eqb x y".
Level 3: Backtrace:

In environment
x, y : t
Heq_anonymous : false = eqb x y
Unable to unify "t" with "false = eqb x y".