LTS Termination Proof

by T2Cert

Input

Integer Transition System

Proof

1 Switch to Cooperation Termination Proof

We consider the following cutpoint-transitions:
3 15 3: x3_post + x3_post ≤ 0x3_postx3_post ≤ 0x3_0 + x3_0 ≤ 0x3_0x3_0 ≤ 0x2_post + x2_post ≤ 0x2_postx2_post ≤ 0x2_0 + x2_0 ≤ 0x2_0x2_0 ≤ 0x1_post + x1_post ≤ 0x1_postx1_post ≤ 0x1_0 + x1_0 ≤ 0x1_0x1_0 ≤ 0x0_post + x0_post ≤ 0x0_postx0_post ≤ 0x0_0 + x0_0 ≤ 0x0_0x0_0 ≤ 0oldX7_post + oldX7_post ≤ 0oldX7_postoldX7_post ≤ 0oldX7_0 + oldX7_0 ≤ 0oldX7_0oldX7_0 ≤ 0oldX6_post + oldX6_post ≤ 0oldX6_postoldX6_post ≤ 0oldX6_0 + oldX6_0 ≤ 0oldX6_0oldX6_0 ≤ 0oldX5_post + oldX5_post ≤ 0oldX5_postoldX5_post ≤ 0oldX5_0 + oldX5_0 ≤ 0oldX5_0oldX5_0 ≤ 0oldX4_post + oldX4_post ≤ 0oldX4_postoldX4_post ≤ 0oldX4_0 + oldX4_0 ≤ 0oldX4_0oldX4_0 ≤ 0oldX3_post + oldX3_post ≤ 0oldX3_postoldX3_post ≤ 0oldX3_0 + oldX3_0 ≤ 0oldX3_0oldX3_0 ≤ 0oldX2_post + oldX2_post ≤ 0oldX2_postoldX2_post ≤ 0oldX2_0 + oldX2_0 ≤ 0oldX2_0oldX2_0 ≤ 0oldX1_post + oldX1_post ≤ 0oldX1_postoldX1_post ≤ 0oldX1_0 + oldX1_0 ≤ 0oldX1_0oldX1_0 ≤ 0oldX0_post + oldX0_post ≤ 0oldX0_postoldX0_post ≤ 0oldX0_0 + oldX0_0 ≤ 0oldX0_0oldX0_0 ≤ 0
and for every transition t, a duplicate t is considered.

2 Transition Removal

We remove transitions 0, 1, 4, 5, 9, 10, 11, 12, 13, 14 using the following ranking functions, which are bounded by −15.

6: 0
5: 0
2: 0
3: 0
4: 0
0: 0
1: 0
6: −6
5: −7
2: −8
3: −8
4: −8
3_var_snapshot: −8
3*: −8
0: −9
1: −10

3 Location Addition

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

3* 18 3: x3_post + x3_post ≤ 0x3_postx3_post ≤ 0x3_0 + x3_0 ≤ 0x3_0x3_0 ≤ 0x2_post + x2_post ≤ 0x2_postx2_post ≤ 0x2_0 + x2_0 ≤ 0x2_0x2_0 ≤ 0x1_post + x1_post ≤ 0x1_postx1_post ≤ 0x1_0 + x1_0 ≤ 0x1_0x1_0 ≤ 0x0_post + x0_post ≤ 0x0_postx0_post ≤ 0x0_0 + x0_0 ≤ 0x0_0x0_0 ≤ 0oldX7_post + oldX7_post ≤ 0oldX7_postoldX7_post ≤ 0oldX7_0 + oldX7_0 ≤ 0oldX7_0oldX7_0 ≤ 0oldX6_post + oldX6_post ≤ 0oldX6_postoldX6_post ≤ 0oldX6_0 + oldX6_0 ≤ 0oldX6_0oldX6_0 ≤ 0oldX5_post + oldX5_post ≤ 0oldX5_postoldX5_post ≤ 0oldX5_0 + oldX5_0 ≤ 0oldX5_0oldX5_0 ≤ 0oldX4_post + oldX4_post ≤ 0oldX4_postoldX4_post ≤ 0oldX4_0 + oldX4_0 ≤ 0oldX4_0oldX4_0 ≤ 0oldX3_post + oldX3_post ≤ 0oldX3_postoldX3_post ≤ 0oldX3_0 + oldX3_0 ≤ 0oldX3_0oldX3_0 ≤ 0oldX2_post + oldX2_post ≤ 0oldX2_postoldX2_post ≤ 0oldX2_0 + oldX2_0 ≤ 0oldX2_0oldX2_0 ≤ 0oldX1_post + oldX1_post ≤ 0oldX1_postoldX1_post ≤ 0oldX1_0 + oldX1_0 ≤ 0oldX1_0oldX1_0 ≤ 0oldX0_post + oldX0_post ≤ 0oldX0_postoldX0_post ≤ 0oldX0_0 + oldX0_0 ≤ 0oldX0_0oldX0_0 ≤ 0

4 Location Addition

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

3 16 3_var_snapshot: x3_post + x3_post ≤ 0x3_postx3_post ≤ 0x3_0 + x3_0 ≤ 0x3_0x3_0 ≤ 0x2_post + x2_post ≤ 0x2_postx2_post ≤ 0x2_0 + x2_0 ≤ 0x2_0x2_0 ≤ 0x1_post + x1_post ≤ 0x1_postx1_post ≤ 0x1_0 + x1_0 ≤ 0x1_0x1_0 ≤ 0x0_post + x0_post ≤ 0x0_postx0_post ≤ 0x0_0 + x0_0 ≤ 0x0_0x0_0 ≤ 0oldX7_post + oldX7_post ≤ 0oldX7_postoldX7_post ≤ 0oldX7_0 + oldX7_0 ≤ 0oldX7_0oldX7_0 ≤ 0oldX6_post + oldX6_post ≤ 0oldX6_postoldX6_post ≤ 0oldX6_0 + oldX6_0 ≤ 0oldX6_0oldX6_0 ≤ 0oldX5_post + oldX5_post ≤ 0oldX5_postoldX5_post ≤ 0oldX5_0 + oldX5_0 ≤ 0oldX5_0oldX5_0 ≤ 0oldX4_post + oldX4_post ≤ 0oldX4_postoldX4_post ≤ 0oldX4_0 + oldX4_0 ≤ 0oldX4_0oldX4_0 ≤ 0oldX3_post + oldX3_post ≤ 0oldX3_postoldX3_post ≤ 0oldX3_0 + oldX3_0 ≤ 0oldX3_0oldX3_0 ≤ 0oldX2_post + oldX2_post ≤ 0oldX2_postoldX2_post ≤ 0oldX2_0 + oldX2_0 ≤ 0oldX2_0oldX2_0 ≤ 0oldX1_post + oldX1_post ≤ 0oldX1_postoldX1_post ≤ 0oldX1_0 + oldX1_0 ≤ 0oldX1_0oldX1_0 ≤ 0oldX0_post + oldX0_post ≤ 0oldX0_postoldX0_post ≤ 0oldX0_0 + oldX0_0 ≤ 0oldX0_0oldX0_0 ≤ 0

5 SCC Decomposition

We consider subproblems for each of the 1 SCC(s) of the program graph.

5.1 SCC Subproblem 1/1

Here we consider the SCC { 2, 3, 4, 3_var_snapshot, 3* }.

5.1.1 Transition Removal

We remove transition 7 using the following ranking functions, which are bounded by 2.

2: −1 + 4⋅x0_0
3: 1 + 4⋅x0_0
4: −1 + 4⋅x0_0
3_var_snapshot: 4⋅x0_0
3*: 2 + 4⋅x0_0

5.1.2 Transition Removal

We remove transition 6 using the following ranking functions, which are bounded by 3.

2: −2 + 5⋅x0_0
3: 1 + 5⋅x0_0
4: −1 + 5⋅x0_0
3_var_snapshot: 5⋅x0_0
3*: 2 + 5⋅x0_0

5.1.3 Transition Removal

We remove transitions 16, 18, 2, 3, 8 using the following ranking functions, which are bounded by −4.

2: 0
3: −2
4: −4
3_var_snapshot: −3
3*: −1

5.1.4 Splitting Cut-Point Transitions

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

5.1.4.1 Cut-Point Subproblem 1/1

Here we consider cut-point transition 15.

5.1.4.1.1 Splitting Cut-Point Transitions

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

Tool configuration

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