**************************************************
Claim
{ termination = Standard
, system = (VAR x1)
(RULES b c -> a b b ,
b a -> a c b)
, deadline = Just
(Time
-2040394096)
}
is false because of
mirror image
R' = { reverse(l) -> reverse(r) | (l -> r) in R }
(VAR x1)
(RULES c b -> b b a ,
a b -> b c a)
admits a looping transport system
notation: http://dfa.imn.htwk-leipzig.de/matchbox/methods/loop.pdf
pivot p = [ b , b ]
block alphabet Gamma = [ [ a ] , [ b ] , [ c ] ]
forall g in Gamma: g p ->^* p phi(g) where
phi = listToFM
[ ( [ a ] , [ [ b ] , [ a ] , [ c ] , [ a ] ] )
, ( [ b ] , [ [ b ] ] ) , ( [ c ] , [ [ a ] , [ b ] ] )
]
phi ([ a ]) = [ [ b ] , [ a ] , [ c ] , [ a ] ]
because of Derivation
{ lhs = [ a , b , b ] , rhs = [ b , b , b , a , c , a ]
, hash_value = -1533806296 , strict = True
, steps = [ Step
{ rule = 1 , position = 0 }
, Step
{ rule = 1 , position = 2 }
, Step
{ rule = 0 , position = 1 }
]
}
phi ([ b ]) = [ [ b ] ]
because of Derivation
{ lhs = [ b ] , rhs = [ b ] , hash_value = -165547832
, strict = False , steps = [ ]
}
phi ([ c ]) = [ [ a ] , [ b ] ]
because of Derivation
{ lhs = [ c , b , b ] , rhs = [ b , b , a , b ]
, hash_value = -507819770 , strict = True
, steps = [ Step
{ rule = 0 , position = 0 }
]
}
start s = [ a ]
exponent k = 3
phi^k(s) contains s (.. p ..)^k
this implies there is a loop starting at s p^k
**************************************************
statistics:
total atomic proof attempts
number = 7, total = 5
maximal = [ Log
{ what = rfc match bounds (classical)
, start = Time
-2040400054
, end = Time
-2040399549
, duration = 5 , success = False
}
]
successful atomic proof attempts
number = 0, total = 0
maximal = [ ]
failed atomic proof attempts
number = 7, total = 5
maximal = [ Log
{ what = rfc match bounds (classical)
, start = Time
-2040400054
, end = Time
-2040399549
, duration = 5 , success = False
}
]
**************************************************
matchbox general information (including details on proof methods):
http://dfa.imn.htwk-leipzig.de/matchbox/
this matchbox implementation uses the SAT solver
MiniSat by Niklas Een and Niklas Sörensson
http://www.cs.chalmers.se/Cs/Research/FormalMethods/MiniSat/
matchbox process information
arguments : --solver=/tmp/tmppwwZvJ/matchbox-2007-06-01/minisat --timeout-command=/tmp/tmppwwZvJ/matchbox-2007-06-01/timeout --tmpdir=tmp --timeout=60 /tmp/tmp.l13R4qXW2h/a.srs
started : Thu Jan 26 12:27:48 CET 2012
finished : Thu Jan 26 12:27:53 CET 2012
run system : Linux uc01-09 2.6.32-5-amd64 #1 SMP Mon Mar 7 21:35:22 UTC 2011 x86_64
release date : Fri Jun 1 17:36:44 CEST 2007
build date : Fri Jun 1 17:36:44 CEST 2007
build system : Linux dfa 2.6.8-2-k7 #1 Tue Aug 16 14:00:15 UTC 2005 i686 GNU/Linux
used clock time: 5 secs