LTS Termination Proof

by AProVE

Input

Integer Transition System

Proof

1 Switch to Cooperation Termination Proof

We consider the following cutpoint-transitions:
l5 l5 l5: x1 = x1x2 = x2x3 = x3x4 = x4x5 = x5x6 = x6x7 = x7
l4 l4 l4: x1 = x1x2 = x2x3 = x3x4 = x4x5 = x5x6 = x6x7 = x7
l7 l7 l7: x1 = x1x2 = x2x3 = x3x4 = x4x5 = x5x6 = x6x7 = x7
l6 l6 l6: x1 = x1x2 = x2x3 = x3x4 = x4x5 = x5x6 = x6x7 = x7
l10 l10 l10: x1 = x1x2 = x2x3 = x3x4 = x4x5 = x5x6 = x6x7 = x7
l11 l11 l11: x1 = x1x2 = x2x3 = x3x4 = x4x5 = x5x6 = x6x7 = x7
l1 l1 l1: x1 = x1x2 = x2x3 = x3x4 = x4x5 = x5x6 = x6x7 = x7
l3 l3 l3: x1 = x1x2 = x2x3 = x3x4 = x4x5 = x5x6 = x6x7 = x7
l0 l0 l0: x1 = x1x2 = x2x3 = x3x4 = x4x5 = x5x6 = x6x7 = x7
l12 l12 l12: x1 = x1x2 = x2x3 = x3x4 = x4x5 = x5x6 = x6x7 = x7
l2 l2 l2: x1 = x1x2 = x2x3 = x3x4 = x4x5 = x5x6 = x6x7 = x7
l9 l9 l9: x1 = x1x2 = x2x3 = x3x4 = x4x5 = x5x6 = x6x7 = x7
and for every transition t, a duplicate t is considered.

2 SCC Decomposition

We consider subproblems for each of the 2 SCC(s) of the program graph.

2.1 SCC Subproblem 1/2

Here we consider the SCC { l5, l10, l1, l0, l2, l9 }.

2.1.1 Transition Removal

We remove transition 3 using the following ranking functions, which are bounded by 0.

l0: 6⋅x1 − 6⋅x3 − 1
l1: 6⋅x1 − 6⋅x3 − 2
l2: −6⋅x3 + 6⋅x1
l5: 6⋅x1 − 6⋅x3 + 1
l9: 6⋅x1 − 6⋅x3 − 4
l10: 6⋅x1 − 6⋅x3 − 3

2.1.2 Transition Removal

We remove transitions 1, 5, 10, 11, 12 using the following ranking functions, which are bounded by −3.

l0: 1
l1: 0
l5: −3
l2: −4
l9: −2
l10: −1

2.1.3 Trivial Cooperation Program

There are no more "sharp" transitions in the cooperation program. Hence the cooperation termination is proved.

2.2 SCC Subproblem 2/2

Here we consider the SCC { l4, l7, l6, l3 }.

2.2.1 Transition Removal

We remove transition 8 using the following ranking functions, which are bounded by 0.

l3: 4⋅x2 − 4⋅x4 + 1
l7: 4⋅x2 − 4⋅x4
l4: 4⋅x2 − 4⋅x4 − 2
l6: 4⋅x2 − 4⋅x4 − 1

2.2.2 Transition Removal

We remove transitions 9, 4, 6 using the following ranking functions, which are bounded by 0.

l3: 0
l7: −1
l4: 1
l6: 2

2.2.3 Trivial Cooperation Program

There are no more "sharp" transitions in the cooperation program. Hence the cooperation termination is proved.

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