LTS Termination Proof

by T2Cert

Input

Integer Transition System

Proof

1 Switch to Cooperation Termination Proof

We consider the following cutpoint-transitions:
1 4 1: x_post + x_post ≤ 0x_postx_post ≤ 0x_1 + x_1 ≤ 0x_1x_1 ≤ 0x_0 + x_0 ≤ 0x_0x_0 ≤ 0
and for every transition t, a duplicate t is considered.

2 Transition Removal

We remove transitions 0, 3 using the following ranking functions, which are bounded by −11.

3: 0
0: 0
1: 0
2: 0
3: −4
0: −5
1: −6
2: −6
1_var_snapshot: −6
1*: −6

3 Location Addition

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

1* 7 1: x_post + x_post ≤ 0x_postx_post ≤ 0x_1 + x_1 ≤ 0x_1x_1 ≤ 0x_0 + x_0 ≤ 0x_0x_0 ≤ 0

4 Location Addition

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

1 5 1_var_snapshot: x_post + x_post ≤ 0x_postx_post ≤ 0x_1 + x_1 ≤ 0x_1x_1 ≤ 0x_0 + x_0 ≤ 0x_0x_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 { 1, 2, 1_var_snapshot, 1* }.

5.1.1 Transition Removal

We remove transition 1 using the following ranking functions, which are bounded by −3.

1: −2 + 4⋅x_0
2: 4⋅x_0
1_var_snapshot: −2 + 4⋅x_0
1*: −1 + 4⋅x_0

5.1.2 Transition Removal

We remove transitions 5, 2 using the following ranking functions, which are bounded by −1.

1: 0
2: 2
1_var_snapshot: −1
1*: 1

5.1.3 Transition Removal

We remove transition 7 using the following ranking functions, which are bounded by −1.

1: −1
2: 0
1_var_snapshot: 0
1*: 0

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 4.

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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