MAYBE

Initial complexity problem:
1:	T:
		(?, 1)    f2(a, b, c) -> f1(a + b, b, d) [ 0 >= a + b + 1 ]
		(?, 1)    f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
		(1, 1)    f300(a, b, c) -> f2(a, b, c)
	start location:	f300
	leaf cost:	0

Repeatedly removing leaves of the complexity graph in problem 1 produces the following problem:
2:	T:
		(?, 1)    f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
		(1, 1)    f300(a, b, c) -> f2(a, b, c)
	start location:	f300
	leaf cost:	1

By chaining the transition f300(a, b, c) -> f2(a, b, c) with all transitions in problem 2, the following new transition is obtained:
	f300(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
We thus obtain the following problem:
3:	T:
		(1, 2)    f300(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
		(?, 1)    f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
	start location:	f300
	leaf cost:	1

By chaining the transition f300(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ] with all transitions in problem 3, the following new transition is obtained:
	f300(a, b, c) -> f2(a + 2*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 ]
We thus obtain the following problem:
4:	T:
		(1, 3)    f300(a, b, c) -> f2(a + 2*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 ]
		(?, 1)    f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
	start location:	f300
	leaf cost:	1

By chaining the transition f300(a, b, c) -> f2(a + 2*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 ] with all transitions in problem 4, the following new transition is obtained:
	f300(a, b, c) -> f2(a + 3*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 ]
We thus obtain the following problem:
5:	T:
		(1, 4)    f300(a, b, c) -> f2(a + 3*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 ]
		(?, 1)    f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
	start location:	f300
	leaf cost:	1

By chaining the transition f300(a, b, c) -> f2(a + 3*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 ] with all transitions in problem 5, the following new transition is obtained:
	f300(a, b, c) -> f2(a + 4*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 ]
We thus obtain the following problem:
6:	T:
		(1, 5)    f300(a, b, c) -> f2(a + 4*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 ]
		(?, 1)    f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
	start location:	f300
	leaf cost:	1

By chaining the transition f300(a, b, c) -> f2(a + 4*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 ] with all transitions in problem 6, the following new transition is obtained:
	f300(a, b, c) -> f2(a + 5*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 ]
We thus obtain the following problem:
7:	T:
		(1, 6)    f300(a, b, c) -> f2(a + 5*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 ]
		(?, 1)    f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
	start location:	f300
	leaf cost:	1

By chaining the transition f300(a, b, c) -> f2(a + 5*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 ] with all transitions in problem 7, the following new transition is obtained:
	f300(a, b, c) -> f2(a + 6*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 ]
We thus obtain the following problem:
8:	T:
		(1, 7)    f300(a, b, c) -> f2(a + 6*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 ]
		(?, 1)    f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
	start location:	f300
	leaf cost:	1

By chaining the transition f300(a, b, c) -> f2(a + 6*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 ] with all transitions in problem 8, the following new transition is obtained:
	f300(a, b, c) -> f2(a + 7*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 ]
We thus obtain the following problem:
9:	T:
		(1, 8)    f300(a, b, c) -> f2(a + 7*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 ]
		(?, 1)    f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
	start location:	f300
	leaf cost:	1

By chaining the transition f300(a, b, c) -> f2(a + 7*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 ] with all transitions in problem 9, the following new transition is obtained:
	f300(a, b, c) -> f2(a + 8*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 ]
We thus obtain the following problem:
10:	T:
		(1, 9)    f300(a, b, c) -> f2(a + 8*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 ]
		(?, 1)    f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
	start location:	f300
	leaf cost:	1

By chaining the transition f300(a, b, c) -> f2(a + 8*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 ] with all transitions in problem 10, the following new transition is obtained:
	f300(a, b, c) -> f2(a + 9*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 ]
We thus obtain the following problem:
11:	T:
		(1, 10)    f300(a, b, c) -> f2(a + 9*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 ]
		(?, 1)     f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
	start location:	f300
	leaf cost:	1

By chaining the transition f300(a, b, c) -> f2(a + 9*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 ] with all transitions in problem 11, the following new transition is obtained:
	f300(a, b, c) -> f2(a + 10*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 ]
We thus obtain the following problem:
12:	T:
		(1, 11)    f300(a, b, c) -> f2(a + 10*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 ]
		(?, 1)     f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
	start location:	f300
	leaf cost:	1

By chaining the transition f300(a, b, c) -> f2(a + 10*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 ] with all transitions in problem 12, the following new transition is obtained:
	f300(a, b, c) -> f2(a + 11*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 /\ a + 11*b >= 0 ]
We thus obtain the following problem:
13:	T:
		(1, 12)    f300(a, b, c) -> f2(a + 11*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 /\ a + 11*b >= 0 ]
		(?, 1)     f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
	start location:	f300
	leaf cost:	1

By chaining the transition f300(a, b, c) -> f2(a + 11*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 /\ a + 11*b >= 0 ] with all transitions in problem 13, the following new transition is obtained:
	f300(a, b, c) -> f2(a + 12*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 /\ a + 11*b >= 0 /\ a + 12*b >= 0 ]
We thus obtain the following problem:
14:	T:
		(1, 13)    f300(a, b, c) -> f2(a + 12*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 /\ a + 11*b >= 0 /\ a + 12*b >= 0 ]
		(?, 1)     f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
	start location:	f300
	leaf cost:	1

By chaining the transition f300(a, b, c) -> f2(a + 12*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 /\ a + 11*b >= 0 /\ a + 12*b >= 0 ] with all transitions in problem 14, the following new transition is obtained:
	f300(a, b, c) -> f2(a + 13*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 /\ a + 11*b >= 0 /\ a + 12*b >= 0 /\ a + 13*b >= 0 ]
We thus obtain the following problem:
15:	T:
		(1, 14)    f300(a, b, c) -> f2(a + 13*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 /\ a + 11*b >= 0 /\ a + 12*b >= 0 /\ a + 13*b >= 0 ]
		(?, 1)     f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
	start location:	f300
	leaf cost:	1

By chaining the transition f300(a, b, c) -> f2(a + 13*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 /\ a + 11*b >= 0 /\ a + 12*b >= 0 /\ a + 13*b >= 0 ] with all transitions in problem 15, the following new transition is obtained:
	f300(a, b, c) -> f2(a + 14*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 /\ a + 11*b >= 0 /\ a + 12*b >= 0 /\ a + 13*b >= 0 /\ a + 14*b >= 0 ]
We thus obtain the following problem:
16:	T:
		(1, 15)    f300(a, b, c) -> f2(a + 14*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 /\ a + 11*b >= 0 /\ a + 12*b >= 0 /\ a + 13*b >= 0 /\ a + 14*b >= 0 ]
		(?, 1)     f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
	start location:	f300
	leaf cost:	1

By chaining the transition f300(a, b, c) -> f2(a + 14*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 /\ a + 11*b >= 0 /\ a + 12*b >= 0 /\ a + 13*b >= 0 /\ a + 14*b >= 0 ] with all transitions in problem 16, the following new transition is obtained:
	f300(a, b, c) -> f2(a + 15*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 /\ a + 11*b >= 0 /\ a + 12*b >= 0 /\ a + 13*b >= 0 /\ a + 14*b >= 0 /\ a + 15*b >= 0 ]
We thus obtain the following problem:
17:	T:
		(1, 16)    f300(a, b, c) -> f2(a + 15*b, b, c) [ a + b >= 0 /\ a + 2*b >= 0 /\ a + 3*b >= 0 /\ a + 4*b >= 0 /\ a + 5*b >= 0 /\ a + 6*b >= 0 /\ a + 7*b >= 0 /\ a + 8*b >= 0 /\ a + 9*b >= 0 /\ a + 10*b >= 0 /\ a + 11*b >= 0 /\ a + 12*b >= 0 /\ a + 13*b >= 0 /\ a + 14*b >= 0 /\ a + 15*b >= 0 ]
		(?, 1)     f2(a, b, c) -> f2(a + b, b, c) [ a + b >= 0 ]
	start location:	f300
	leaf cost:	1

Complexity upper bound ?

Time: 2.414 sec (SMT: 2.303 sec)