Goal:
  
  G : t
  HI : invariants G
  HG : acyclic_no_loop G
  n : Z
  x : V.t
  y : V.t
  n0 : x = y -> False
  ============================
   (false = true <-> x = y)


DEBUG:Going to execute:
<Coq.Init.Tauto.flatten_contravariant_conj> flags X1 X2 id
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 2: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 2: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 2: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 2: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 2: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 2: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".
Level 1: Backtrace:

In environment
G : t
HI : invariants G
HG : acyclic_no_loop G
n : Z
x, y : V.t
n0 : x = y -> False
Unable to unify "y" with "x".