LTS Termination Proof

by T2Cert

Input

Integer Transition System

Proof

1 Invariant Updates

The following invariants are asserted.

0: TRUE
1: arg1P ≤ 0arg1 ≤ 0
2: TRUE
3: 1 − arg2 ≤ 0arg3 ≤ 0
4: x37 ≤ 0x36 ≤ 0
5: TRUE

The invariants are proved as follows.

IMPACT Invariant Proof

2 Switch to Cooperation Termination Proof

We consider the following cutpoint-transitions:
2 12 2: x83 + x83 ≤ 0x83x83 ≤ 0x77 + x77 ≤ 0x77x77 ≤ 0x76 + x76 ≤ 0x76x76 ≤ 0x75 + x75 ≤ 0x75x75 ≤ 0x71 + x71 ≤ 0x71x71 ≤ 0x70 + x70 ≤ 0x70x70 ≤ 0x63 + x63 ≤ 0x63x63 ≤ 0x62 + x62 ≤ 0x62x62 ≤ 0x61 + x61 ≤ 0x61x61 ≤ 0x60 + x60 ≤ 0x60x60 ≤ 0x59 + x59 ≤ 0x59x59 ≤ 0x55 + x55 ≤ 0x55x55 ≤ 0x54 + x54 ≤ 0x54x54 ≤ 0x53 + x53 ≤ 0x53x53 ≤ 0x52 + x52 ≤ 0x52x52 ≤ 0x5 + x5 ≤ 0x5x5 ≤ 0x45 + x45 ≤ 0x45x45 ≤ 0x44 + x44 ≤ 0x44x44 ≤ 0x43 + x43 ≤ 0x43x43 ≤ 0x42 + x42 ≤ 0x42x42 ≤ 0x41 + x41 ≤ 0x41x41 ≤ 0x40 + x40 ≤ 0x40x40 ≤ 0x4 + x4 ≤ 0x4x4 ≤ 0x39 + x39 ≤ 0x39x39 ≤ 0x37 + x37 ≤ 0x37x37 ≤ 0x36 + x36 ≤ 0x36x36 ≤ 0x10 + x10 ≤ 0x10x10 ≤ 0arg3P + arg3P ≤ 0arg3Parg3P ≤ 0arg3 + arg3 ≤ 0arg3arg3 ≤ 0arg2P + arg2P ≤ 0arg2Parg2P ≤ 0arg2 + arg2 ≤ 0arg2arg2 ≤ 0arg1P + arg1P ≤ 0arg1Parg1P ≤ 0arg1 + arg1 ≤ 0arg1arg1 ≤ 0
4 19 4: x83 + x83 ≤ 0x83x83 ≤ 0x77 + x77 ≤ 0x77x77 ≤ 0x76 + x76 ≤ 0x76x76 ≤ 0x75 + x75 ≤ 0x75x75 ≤ 0x71 + x71 ≤ 0x71x71 ≤ 0x70 + x70 ≤ 0x70x70 ≤ 0x63 + x63 ≤ 0x63x63 ≤ 0x62 + x62 ≤ 0x62x62 ≤ 0x61 + x61 ≤ 0x61x61 ≤ 0x60 + x60 ≤ 0x60x60 ≤ 0x59 + x59 ≤ 0x59x59 ≤ 0x55 + x55 ≤ 0x55x55 ≤ 0x54 + x54 ≤ 0x54x54 ≤ 0x53 + x53 ≤ 0x53x53 ≤ 0x52 + x52 ≤ 0x52x52 ≤ 0x5 + x5 ≤ 0x5x5 ≤ 0x45 + x45 ≤ 0x45x45 ≤ 0x44 + x44 ≤ 0x44x44 ≤ 0x43 + x43 ≤ 0x43x43 ≤ 0x42 + x42 ≤ 0x42x42 ≤ 0x41 + x41 ≤ 0x41x41 ≤ 0x40 + x40 ≤ 0x40x40 ≤ 0x4 + x4 ≤ 0x4x4 ≤ 0x39 + x39 ≤ 0x39x39 ≤ 0x37 + x37 ≤ 0x37x37 ≤ 0x36 + x36 ≤ 0x36x36 ≤ 0x10 + x10 ≤ 0x10x10 ≤ 0arg3P + arg3P ≤ 0arg3Parg3P ≤ 0arg3 + arg3 ≤ 0arg3arg3 ≤ 0arg2P + arg2P ≤ 0arg2Parg2P ≤ 0arg2 + arg2 ≤ 0arg2arg2 ≤ 0arg1P + arg1P ≤ 0arg1Parg1P ≤ 0arg1 + arg1 ≤ 0arg1arg1 ≤ 0
and for every transition t, a duplicate t is considered.

3 Transition Removal

We remove transitions 0, 1, 2, 9, 11 using the following ranking functions, which are bounded by −17.

5: 0
0: 0
1: 0
2: 0
3: 0
4: 0
5: −6
0: −7
1: −8
2: −9
3: −9
2_var_snapshot: −9
2*: −9
4: −12
4_var_snapshot: −12
4*: −12

4 Location Addition

The following skip-transition is inserted and corresponding redirections w.r.t. the old location are performed.

2* 15 2: x83 + x83 ≤ 0x83x83 ≤ 0x77 + x77 ≤ 0x77x77 ≤ 0x76 + x76 ≤ 0x76x76 ≤ 0x75 + x75 ≤ 0x75x75 ≤ 0x71 + x71 ≤ 0x71x71 ≤ 0x70 + x70 ≤ 0x70x70 ≤ 0x63 + x63 ≤ 0x63x63 ≤ 0x62 + x62 ≤ 0x62x62 ≤ 0x61 + x61 ≤ 0x61x61 ≤ 0x60 + x60 ≤ 0x60x60 ≤ 0x59 + x59 ≤ 0x59x59 ≤ 0x55 + x55 ≤ 0x55x55 ≤ 0x54 + x54 ≤ 0x54x54 ≤ 0x53 + x53 ≤ 0x53x53 ≤ 0x52 + x52 ≤ 0x52x52 ≤ 0x5 + x5 ≤ 0x5x5 ≤ 0x45 + x45 ≤ 0x45x45 ≤ 0x44 + x44 ≤ 0x44x44 ≤ 0x43 + x43 ≤ 0x43x43 ≤ 0x42 + x42 ≤ 0x42x42 ≤ 0x41 + x41 ≤ 0x41x41 ≤ 0x40 + x40 ≤ 0x40x40 ≤ 0x4 + x4 ≤ 0x4x4 ≤ 0x39 + x39 ≤ 0x39x39 ≤ 0x37 + x37 ≤ 0x37x37 ≤ 0x36 + x36 ≤ 0x36x36 ≤ 0x10 + x10 ≤ 0x10x10 ≤ 0arg3P + arg3P ≤ 0arg3Parg3P ≤ 0arg3 + arg3 ≤ 0arg3arg3 ≤ 0arg2P + arg2P ≤ 0arg2Parg2P ≤ 0arg2 + arg2 ≤ 0arg2arg2 ≤ 0arg1P + arg1P ≤ 0arg1Parg1P ≤ 0arg1 + arg1 ≤ 0arg1arg1 ≤ 0

5 Location Addition

The following skip-transition is inserted and corresponding redirections w.r.t. the old location are performed.

2 13 2_var_snapshot: x83 + x83 ≤ 0x83x83 ≤ 0x77 + x77 ≤ 0x77x77 ≤ 0x76 + x76 ≤ 0x76x76 ≤ 0x75 + x75 ≤ 0x75x75 ≤ 0x71 + x71 ≤ 0x71x71 ≤ 0x70 + x70 ≤ 0x70x70 ≤ 0x63 + x63 ≤ 0x63x63 ≤ 0x62 + x62 ≤ 0x62x62 ≤ 0x61 + x61 ≤ 0x61x61 ≤ 0x60 + x60 ≤ 0x60x60 ≤ 0x59 + x59 ≤ 0x59x59 ≤ 0x55 + x55 ≤ 0x55x55 ≤ 0x54 + x54 ≤ 0x54x54 ≤ 0x53 + x53 ≤ 0x53x53 ≤ 0x52 + x52 ≤ 0x52x52 ≤ 0x5 + x5 ≤ 0x5x5 ≤ 0x45 + x45 ≤ 0x45x45 ≤ 0x44 + x44 ≤ 0x44x44 ≤ 0x43 + x43 ≤ 0x43x43 ≤ 0x42 + x42 ≤ 0x42x42 ≤ 0x41 + x41 ≤ 0x41x41 ≤ 0x40 + x40 ≤ 0x40x40 ≤ 0x4 + x4 ≤ 0x4x4 ≤ 0x39 + x39 ≤ 0x39x39 ≤ 0x37 + x37 ≤ 0x37x37 ≤ 0x36 + x36 ≤ 0x36x36 ≤ 0x10 + x10 ≤ 0x10x10 ≤ 0arg3P + arg3P ≤ 0arg3Parg3P ≤ 0arg3 + arg3 ≤ 0arg3arg3 ≤ 0arg2P + arg2P ≤ 0arg2Parg2P ≤ 0arg2 + arg2 ≤ 0arg2arg2 ≤ 0arg1P + arg1P ≤ 0arg1Parg1P ≤ 0arg1 + arg1 ≤ 0arg1arg1 ≤ 0

6 Location Addition

The following skip-transition is inserted and corresponding redirections w.r.t. the old location are performed.

4* 22 4: x83 + x83 ≤ 0x83x83 ≤ 0x77 + x77 ≤ 0x77x77 ≤ 0x76 + x76 ≤ 0x76x76 ≤ 0x75 + x75 ≤ 0x75x75 ≤ 0x71 + x71 ≤ 0x71x71 ≤ 0x70 + x70 ≤ 0x70x70 ≤ 0x63 + x63 ≤ 0x63x63 ≤ 0x62 + x62 ≤ 0x62x62 ≤ 0x61 + x61 ≤ 0x61x61 ≤ 0x60 + x60 ≤ 0x60x60 ≤ 0x59 + x59 ≤ 0x59x59 ≤ 0x55 + x55 ≤ 0x55x55 ≤ 0x54 + x54 ≤ 0x54x54 ≤ 0x53 + x53 ≤ 0x53x53 ≤ 0x52 + x52 ≤ 0x52x52 ≤ 0x5 + x5 ≤ 0x5x5 ≤ 0x45 + x45 ≤ 0x45x45 ≤ 0x44 + x44 ≤ 0x44x44 ≤ 0x43 + x43 ≤ 0x43x43 ≤ 0x42 + x42 ≤ 0x42x42 ≤ 0x41 + x41 ≤ 0x41x41 ≤ 0x40 + x40 ≤ 0x40x40 ≤ 0x4 + x4 ≤ 0x4x4 ≤ 0x39 + x39 ≤ 0x39x39 ≤ 0x37 + x37 ≤ 0x37x37 ≤ 0x36 + x36 ≤ 0x36x36 ≤ 0x10 + x10 ≤ 0x10x10 ≤ 0arg3P + arg3P ≤ 0arg3Parg3P ≤ 0arg3 + arg3 ≤ 0arg3arg3 ≤ 0arg2P + arg2P ≤ 0arg2Parg2P ≤ 0arg2 + arg2 ≤ 0arg2arg2 ≤ 0arg1P + arg1P ≤ 0arg1Parg1P ≤ 0arg1 + arg1 ≤ 0arg1arg1 ≤ 0

7 Location Addition

The following skip-transition is inserted and corresponding redirections w.r.t. the old location are performed.

4 20 4_var_snapshot: x83 + x83 ≤ 0x83x83 ≤ 0x77 + x77 ≤ 0x77x77 ≤ 0x76 + x76 ≤ 0x76x76 ≤ 0x75 + x75 ≤ 0x75x75 ≤ 0x71 + x71 ≤ 0x71x71 ≤ 0x70 + x70 ≤ 0x70x70 ≤ 0x63 + x63 ≤ 0x63x63 ≤ 0x62 + x62 ≤ 0x62x62 ≤ 0x61 + x61 ≤ 0x61x61 ≤ 0x60 + x60 ≤ 0x60x60 ≤ 0x59 + x59 ≤ 0x59x59 ≤ 0x55 + x55 ≤ 0x55x55 ≤ 0x54 + x54 ≤ 0x54x54 ≤ 0x53 + x53 ≤ 0x53x53 ≤ 0x52 + x52 ≤ 0x52x52 ≤ 0x5 + x5 ≤ 0x5x5 ≤ 0x45 + x45 ≤ 0x45x45 ≤ 0x44 + x44 ≤ 0x44x44 ≤ 0x43 + x43 ≤ 0x43x43 ≤ 0x42 + x42 ≤ 0x42x42 ≤ 0x41 + x41 ≤ 0x41x41 ≤ 0x40 + x40 ≤ 0x40x40 ≤ 0x4 + x4 ≤ 0x4x4 ≤ 0x39 + x39 ≤ 0x39x39 ≤ 0x37 + x37 ≤ 0x37x37 ≤ 0x36 + x36 ≤ 0x36x36 ≤ 0x10 + x10 ≤ 0x10x10 ≤ 0arg3P + arg3P ≤ 0arg3Parg3P ≤ 0arg3 + arg3 ≤ 0arg3arg3 ≤ 0arg2P + arg2P ≤ 0arg2Parg2P ≤ 0arg2 + arg2 ≤ 0arg2arg2 ≤ 0arg1P + arg1P ≤ 0arg1Parg1P ≤ 0arg1 + arg1 ≤ 0arg1arg1 ≤ 0

8 SCC Decomposition

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

8.1 SCC Subproblem 1/2

Here we consider the SCC { 2, 3, 2_var_snapshot, 2* }.

8.1.1 Transition Removal

We remove transitions 3, 4, 5, 6, 7, 8 using the following ranking functions, which are bounded by 3.

2: 2 + 4⋅arg2
3: 4⋅arg2
2_var_snapshot: 1 + 4⋅arg2
2*: 3 + 4⋅arg2

8.1.2 Transition Removal

We remove transition 15 using the following ranking functions, which are bounded by −1.

2: 0
3: 0
2_var_snapshot: −1
2*: 1

8.1.3 Transition Removal

We remove transition 13 using the following ranking functions, which are bounded by −1.

2: 0
3: 0
2_var_snapshot: −1
2*: 0

8.1.4 Splitting Cut-Point Transitions

We consider 1 subproblems corresponding to sets of cut-point transitions as follows.

8.1.4.1 Cut-Point Subproblem 1/1

Here we consider cut-point transition 12.

8.1.4.1.1 Splitting Cut-Point Transitions

There remain no cut-point transition to consider. Hence the cooperation termination is trivial.

8.2 SCC Subproblem 2/2

Here we consider the SCC { 4, 4_var_snapshot, 4* }.

8.2.1 Transition Removal

We remove transition 10 using the following ranking functions, which are bounded by 2.

4: 1 + 3⋅arg1
4_var_snapshot: 3⋅arg1
4*: 2 + 3⋅arg1

8.2.2 Transition Removal

We remove transition 22 using the following ranking functions, which are bounded by −2.

4: −1
4_var_snapshot: −2
4*: 0

8.2.3 Transition Removal

We remove transition 20 using the following ranking functions, which are bounded by −1.

4: 0
4_var_snapshot: −1
4*: 0

8.2.4 Splitting Cut-Point Transitions

We consider 1 subproblems corresponding to sets of cut-point transitions as follows.

8.2.4.1 Cut-Point Subproblem 1/1

Here we consider cut-point transition 19.

8.2.4.1.1 Splitting Cut-Point Transitions

There remain no cut-point transition to consider. Hence the cooperation termination is trivial.

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