Goal:
    x : V.t  y : V.t  p : VSet.t  a : V.t  H0 : y = a
  ============================
   (x = a)


DEBUG:Going to execute:
<Coq.Init.Tauto.is_empty> flags X1; elim H
Level 4: Backtrace:

In environment
x, y : V.t
p : VSet.t
a : V.t
H0 : y = a
Unable to unify "a" with "x".
Level 4: Backtrace:

In environment
x, y : V.t
p : VSet.t
a : V.t
H0 : y = a
Unable to unify "a" with "x".
Level 5: Backtrace:

In environment
x, y : V.t
p : VSet.t
a : V.t
H0 : y = a
Unable to unify "a" with "x".
Level 5: Backtrace:

In environment
x, y : V.t
p : VSet.t
a : V.t
H0 : y = a
Unable to unify "a" with "x".
Level 4: Backtrace:

In environment
x, y : V.t
p : VSet.t
a : V.t
H0 : y = a
Unable to unify "a" with "x".
Level 4: Backtrace:

In environment
x, y : V.t
p : VSet.t
a : V.t
H0 : y = a
Unable to unify "a" with "x".