LTS Termination Proof

by T2Cert

Input

Integer Transition System

Proof

1 Switch to Cooperation Termination Proof

We consider the following cutpoint-transitions:
2 5 2: tmp_post + tmp_post ≤ 0tmp_posttmp_post ≤ 0tmp_0 + tmp_0 ≤ 0tmp_0tmp_0 ≤ 0temp7_post + temp7_post ≤ 0temp7_posttemp7_post ≤ 0temp7_0 + temp7_0 ≤ 0temp7_0temp7_0 ≤ 0ret_fib9_post + ret_fib9_post ≤ 0ret_fib9_postret_fib9_post ≤ 0ret_fib9_0 + ret_fib9_0 ≤ 0ret_fib9_0ret_fib9_0 ≤ 0n3_post + n3_post ≤ 0n3_postn3_post ≤ 0n3_0 + n3_0 ≤ 0n3_0n3_0 ≤ 0i4_post + i4_post ≤ 0i4_posti4_post ≤ 0i4_0 + i4_0 ≤ 0i4_0i4_0 ≤ 0ans8_post + ans8_post ≤ 0ans8_postans8_post ≤ 0ans8_0 + ans8_0 ≤ 0ans8_0ans8_0 ≤ 0a_post + a_post ≤ 0a_posta_post ≤ 0a_0 + a_0 ≤ 0a_0a_0 ≤ 0___const_30_0 + ___const_30_0 ≤ 0___const_30_0___const_30_0 ≤ 0Fold6_post + Fold6_post ≤ 0Fold6_postFold6_post ≤ 0Fold6_0 + Fold6_0 ≤ 0Fold6_0Fold6_0 ≤ 0Fnew5_post + Fnew5_post ≤ 0Fnew5_postFnew5_post ≤ 0Fnew5_0 + Fnew5_0 ≤ 0Fnew5_0Fnew5_0 ≤ 0
and for every transition t, a duplicate t is considered.

2 Transition Removal

We remove transitions 0, 3, 4 using the following ranking functions, which are bounded by −13.

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

3 Location Addition

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

2* 8 2: tmp_post + tmp_post ≤ 0tmp_posttmp_post ≤ 0tmp_0 + tmp_0 ≤ 0tmp_0tmp_0 ≤ 0temp7_post + temp7_post ≤ 0temp7_posttemp7_post ≤ 0temp7_0 + temp7_0 ≤ 0temp7_0temp7_0 ≤ 0ret_fib9_post + ret_fib9_post ≤ 0ret_fib9_postret_fib9_post ≤ 0ret_fib9_0 + ret_fib9_0 ≤ 0ret_fib9_0ret_fib9_0 ≤ 0n3_post + n3_post ≤ 0n3_postn3_post ≤ 0n3_0 + n3_0 ≤ 0n3_0n3_0 ≤ 0i4_post + i4_post ≤ 0i4_posti4_post ≤ 0i4_0 + i4_0 ≤ 0i4_0i4_0 ≤ 0ans8_post + ans8_post ≤ 0ans8_postans8_post ≤ 0ans8_0 + ans8_0 ≤ 0ans8_0ans8_0 ≤ 0a_post + a_post ≤ 0a_posta_post ≤ 0a_0 + a_0 ≤ 0a_0a_0 ≤ 0___const_30_0 + ___const_30_0 ≤ 0___const_30_0___const_30_0 ≤ 0Fold6_post + Fold6_post ≤ 0Fold6_postFold6_post ≤ 0Fold6_0 + Fold6_0 ≤ 0Fold6_0Fold6_0 ≤ 0Fnew5_post + Fnew5_post ≤ 0Fnew5_postFnew5_post ≤ 0Fnew5_0 + Fnew5_0 ≤ 0Fnew5_0Fnew5_0 ≤ 0

4 Location Addition

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

2 6 2_var_snapshot: tmp_post + tmp_post ≤ 0tmp_posttmp_post ≤ 0tmp_0 + tmp_0 ≤ 0tmp_0tmp_0 ≤ 0temp7_post + temp7_post ≤ 0temp7_posttemp7_post ≤ 0temp7_0 + temp7_0 ≤ 0temp7_0temp7_0 ≤ 0ret_fib9_post + ret_fib9_post ≤ 0ret_fib9_postret_fib9_post ≤ 0ret_fib9_0 + ret_fib9_0 ≤ 0ret_fib9_0ret_fib9_0 ≤ 0n3_post + n3_post ≤ 0n3_postn3_post ≤ 0n3_0 + n3_0 ≤ 0n3_0n3_0 ≤ 0i4_post + i4_post ≤ 0i4_posti4_post ≤ 0i4_0 + i4_0 ≤ 0i4_0i4_0 ≤ 0ans8_post + ans8_post ≤ 0ans8_postans8_post ≤ 0ans8_0 + ans8_0 ≤ 0ans8_0ans8_0 ≤ 0a_post + a_post ≤ 0a_posta_post ≤ 0a_0 + a_0 ≤ 0a_0a_0 ≤ 0___const_30_0 + ___const_30_0 ≤ 0___const_30_0___const_30_0 ≤ 0Fold6_post + Fold6_post ≤ 0Fold6_postFold6_post ≤ 0Fold6_0 + Fold6_0 ≤ 0Fold6_0Fold6_0 ≤ 0Fnew5_post + Fnew5_post ≤ 0Fnew5_postFnew5_post ≤ 0Fnew5_0 + Fnew5_0 ≤ 0Fnew5_0Fnew5_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 { 0, 2, 2_var_snapshot, 2* }.

5.1.1 Transition Removal

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

0: −1 − 4⋅i4_0 + 4⋅n3_0
2: 1 − 4⋅i4_0 + 4⋅n3_0
2_var_snapshot: −4⋅i4_0 + 4⋅n3_0
2*: 2 − 4⋅i4_0 + 4⋅n3_0

5.1.2 Transition Removal

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

0: −3
2: −1
2_var_snapshot: −2
2*: 0

5.1.3 Splitting Cut-Point Transitions

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

5.1.3.1 Cut-Point Subproblem 1/1

Here we consider cut-point transition 5.

5.1.3.1.1 Splitting Cut-Point Transitions

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

Tool configuration

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