LTS Termination Proof

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Input

Integer Transition System

Proof

1 Invariant Updates

The following invariants are asserted.

0: TRUE
1: 1 − arg1P ≤ 03 − arg2P ≤ 01 − arg1 ≤ 03 − arg2 ≤ 0
3: 3 − arg1P ≤ 0arg2P ≤ 03 − arg1 ≤ 0arg2 ≤ 0
4: arg1P ≤ 0arg2P ≤ 0arg1 ≤ 0arg2 ≤ 0
5: 1 − arg1P ≤ 0arg2P ≤ 01 − arg1 ≤ 0arg2 ≤ 0arg3 ≤ 0
6: TRUE

The invariants are proved as follows.

IMPACT Invariant Proof

2 Switch to Cooperation Termination Proof

We consider the following cutpoint-transitions:
3 16 3: x90 + x90 ≤ 0x90x90 ≤ 0x83 + x83 ≤ 0x83x83 ≤ 0x75 + x75 ≤ 0x75x75 ≤ 0x56 + x56 ≤ 0x56x56 ≤ 0x37 + x37 ≤ 0x37x37 ≤ 0x30 + x30 ≤ 0x30x30 ≤ 0arg5P + arg5P ≤ 0arg5Parg5P ≤ 0arg5 + arg5 ≤ 0arg5arg5 ≤ 0arg4P + arg4P ≤ 0arg4Parg4P ≤ 0arg4 + arg4 ≤ 0arg4arg4 ≤ 0arg3P + arg3P ≤ 0arg3Parg3P ≤ 0arg3 + arg3 ≤ 0arg3arg3 ≤ 0arg2P + arg2P ≤ 0arg2Parg2P ≤ 0arg2 + arg2 ≤ 0arg2arg2 ≤ 0arg1P + arg1P ≤ 0arg1Parg1P ≤ 0arg1 + arg1 ≤ 0arg1arg1 ≤ 0
4 23 4: x90 + x90 ≤ 0x90x90 ≤ 0x83 + x83 ≤ 0x83x83 ≤ 0x75 + x75 ≤ 0x75x75 ≤ 0x56 + x56 ≤ 0x56x56 ≤ 0x37 + x37 ≤ 0x37x37 ≤ 0x30 + x30 ≤ 0x30x30 ≤ 0arg5P + arg5P ≤ 0arg5Parg5P ≤ 0arg5 + arg5 ≤ 0arg5arg5 ≤ 0arg4P + arg4P ≤ 0arg4Parg4P ≤ 0arg4 + arg4 ≤ 0arg4arg4 ≤ 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, 2, 9, 10, 15 using the following ranking functions, which are bounded by −17.

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

3* 19 3: x90 + x90 ≤ 0x90x90 ≤ 0x83 + x83 ≤ 0x83x83 ≤ 0x75 + x75 ≤ 0x75x75 ≤ 0x56 + x56 ≤ 0x56x56 ≤ 0x37 + x37 ≤ 0x37x37 ≤ 0x30 + x30 ≤ 0x30x30 ≤ 0arg5P + arg5P ≤ 0arg5Parg5P ≤ 0arg5 + arg5 ≤ 0arg5arg5 ≤ 0arg4P + arg4P ≤ 0arg4Parg4P ≤ 0arg4 + arg4 ≤ 0arg4arg4 ≤ 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.

3 17 3_var_snapshot: x90 + x90 ≤ 0x90x90 ≤ 0x83 + x83 ≤ 0x83x83 ≤ 0x75 + x75 ≤ 0x75x75 ≤ 0x56 + x56 ≤ 0x56x56 ≤ 0x37 + x37 ≤ 0x37x37 ≤ 0x30 + x30 ≤ 0x30x30 ≤ 0arg5P + arg5P ≤ 0arg5Parg5P ≤ 0arg5 + arg5 ≤ 0arg5arg5 ≤ 0arg4P + arg4P ≤ 0arg4Parg4P ≤ 0arg4 + arg4 ≤ 0arg4arg4 ≤ 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* 26 4: x90 + x90 ≤ 0x90x90 ≤ 0x83 + x83 ≤ 0x83x83 ≤ 0x75 + x75 ≤ 0x75x75 ≤ 0x56 + x56 ≤ 0x56x56 ≤ 0x37 + x37 ≤ 0x37x37 ≤ 0x30 + x30 ≤ 0x30x30 ≤ 0arg5P + arg5P ≤ 0arg5Parg5P ≤ 0arg5 + arg5 ≤ 0arg5arg5 ≤ 0arg4P + arg4P ≤ 0arg4Parg4P ≤ 0arg4 + arg4 ≤ 0arg4arg4 ≤ 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 24 4_var_snapshot: x90 + x90 ≤ 0x90x90 ≤ 0x83 + x83 ≤ 0x83x83 ≤ 0x75 + x75 ≤ 0x75x75 ≤ 0x56 + x56 ≤ 0x56x56 ≤ 0x37 + x37 ≤ 0x37x37 ≤ 0x30 + x30 ≤ 0x30x30 ≤ 0arg5P + arg5P ≤ 0arg5Parg5P ≤ 0arg5 + arg5 ≤ 0arg5arg5 ≤ 0arg4P + arg4P ≤ 0arg4Parg4P ≤ 0arg4 + arg4 ≤ 0arg4arg4 ≤ 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 { 3, 3_var_snapshot, 3* }.

8.1.1 Transition Removal

We remove transitions 3, 4, 5, 6, 7, 8 using the following ranking functions, which are bounded by 2.

3: 1 + 3⋅arg3
3_var_snapshot: 3⋅arg3
3*: 2 + 3⋅arg3

8.1.2 Transition Removal

We remove transition 19 using the following ranking functions, which are bounded by −1.

3: 0
3_var_snapshot: −1
3*: 1

8.1.3 Transition Removal

We remove transition 17 using the following ranking functions, which are bounded by −1.

3: 0
3_var_snapshot: −1
3*: 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 16.

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, 5, 4_var_snapshot, 4* }.

8.2.1 Transition Removal

We remove transitions 24, 26, 12, 13, 14 using the following ranking functions, which are bounded by −4.

4: −2 + 4⋅arg1
5: 4⋅arg2
4_var_snapshot: −3 + 4⋅arg1
4*: −1 + 4⋅arg1

8.2.2 Transition Removal

We remove transition 11 using the following ranking functions, which are bounded by −1.

4: 0
5: −1
4_var_snapshot: 0
4*: 0

8.2.3 Splitting Cut-Point Transitions

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

8.2.3.1 Cut-Point Subproblem 1/1

Here we consider cut-point transition 23.

8.2.3.1.1 Splitting Cut-Point Transitions

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

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