Goal:
  
  x : V.t
  y : V.t
  p : VSet.t
  H : x = y -> False
  a : V.t
  H0 : y = a -> False
  H2 : x = a
  ============================
   (x = a)


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

In environment
x, y : V.t
p : VSet.t
H : x = y -> False
a : V.t
H0 : y = a -> False
H2 : x = a
Unable to unify "a" with "x".
Level 4: Backtrace:

In environment
x, y : V.t
p : VSet.t
H : x = y -> False
a : V.t
H0 : y = a -> False
H2 : x = a
Unable to unify "a" with "x".
Level 5: Backtrace:

In environment
x, y : V.t
p : VSet.t
H : x = y -> False
a : V.t
H0 : y = a -> False
H2 : x = a
Unable to unify "a" with "x".
Level 5: Backtrace:

In environment
x, y : V.t
p : VSet.t
H : x = y -> False
a : V.t
H0 : y = a -> False
H2 : x = a
Unable to unify "a" with "x".
Level 4: Backtrace:

In environment
x, y : V.t
p : VSet.t
H : x = y -> False
a : V.t
H0 : y = a -> False
H2 : x = a
Unable to unify "a" with "x".
Level 4: Backtrace:

In environment
x, y : V.t
p : VSet.t
H : x = y -> False
a : V.t
H0 : y = a -> False
H2 : x = a
Unable to unify "a" with "x".