MAYBE

Initial complexity problem:
1:	T:
		(?, 1)    f0(a, b, c) -> f2(a, d, c) [ 0 >= a ]
		(?, 1)    f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
		(1, 1)    f1(a, b, c) -> f0(a, b, c)
	start location:	f1
	leaf cost:	0

Repeatedly removing leaves of the complexity graph in problem 1 produces the following problem:
2:	T:
		(?, 1)    f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
		(1, 1)    f1(a, b, c) -> f0(a, b, c)
	start location:	f1
	leaf cost:	1

By chaining the transition f1(a, b, c) -> f0(a, b, c) with all transitions in problem 2, the following new transition is obtained:
	f1(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
We thus obtain the following problem:
3:	T:
		(1, 2)    f1(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
		(?, 1)    f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
	start location:	f1
	leaf cost:	1

By chaining the transition f1(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ] with all transitions in problem 3, the following new transition is obtained:
	f1(a, b, c) -> f0(a + 2*c - 1, b, c - 2) [ a >= 1 /\ a + c >= 1 ]
We thus obtain the following problem:
4:	T:
		(1, 3)    f1(a, b, c) -> f0(a + 2*c - 1, b, c - 2) [ a >= 1 /\ a + c >= 1 ]
		(?, 1)    f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
	start location:	f1
	leaf cost:	1

By chaining the transition f1(a, b, c) -> f0(a + 2*c - 1, b, c - 2) [ a >= 1 /\ a + c >= 1 ] with all transitions in problem 4, the following new transition is obtained:
	f1(a, b, c) -> f0(a + 3*c - 3, b, c - 3) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 ]
We thus obtain the following problem:
5:	T:
		(1, 4)    f1(a, b, c) -> f0(a + 3*c - 3, b, c - 3) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 ]
		(?, 1)    f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
	start location:	f1
	leaf cost:	1

By chaining the transition f1(a, b, c) -> f0(a + 3*c - 3, b, c - 3) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 ] with all transitions in problem 5, the following new transition is obtained:
	f1(a, b, c) -> f0(a + 4*c - 6, b, c - 4) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 ]
We thus obtain the following problem:
6:	T:
		(1, 5)    f1(a, b, c) -> f0(a + 4*c - 6, b, c - 4) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 ]
		(?, 1)    f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
	start location:	f1
	leaf cost:	1

By chaining the transition f1(a, b, c) -> f0(a + 4*c - 6, b, c - 4) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 ] with all transitions in problem 6, the following new transition is obtained:
	f1(a, b, c) -> f0(a + 5*c - 10, b, c - 5) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 ]
We thus obtain the following problem:
7:	T:
		(1, 6)    f1(a, b, c) -> f0(a + 5*c - 10, b, c - 5) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 ]
		(?, 1)    f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
	start location:	f1
	leaf cost:	1

By chaining the transition f1(a, b, c) -> f0(a + 5*c - 10, b, c - 5) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 ] with all transitions in problem 7, the following new transition is obtained:
	f1(a, b, c) -> f0(a + 6*c - 15, b, c - 6) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 ]
We thus obtain the following problem:
8:	T:
		(1, 7)    f1(a, b, c) -> f0(a + 6*c - 15, b, c - 6) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 ]
		(?, 1)    f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
	start location:	f1
	leaf cost:	1

By chaining the transition f1(a, b, c) -> f0(a + 6*c - 15, b, c - 6) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 ] with all transitions in problem 8, the following new transition is obtained:
	f1(a, b, c) -> f0(a + 7*c - 21, b, c - 7) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 ]
We thus obtain the following problem:
9:	T:
		(1, 8)    f1(a, b, c) -> f0(a + 7*c - 21, b, c - 7) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 ]
		(?, 1)    f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
	start location:	f1
	leaf cost:	1

By chaining the transition f1(a, b, c) -> f0(a + 7*c - 21, b, c - 7) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 ] with all transitions in problem 9, the following new transition is obtained:
	f1(a, b, c) -> f0(a + 8*c - 28, b, c - 8) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 ]
We thus obtain the following problem:
10:	T:
		(1, 9)    f1(a, b, c) -> f0(a + 8*c - 28, b, c - 8) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 ]
		(?, 1)    f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
	start location:	f1
	leaf cost:	1

By chaining the transition f1(a, b, c) -> f0(a + 8*c - 28, b, c - 8) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 ] with all transitions in problem 10, the following new transition is obtained:
	f1(a, b, c) -> f0(a + 9*c - 36, b, c - 9) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 ]
We thus obtain the following problem:
11:	T:
		(1, 10)    f1(a, b, c) -> f0(a + 9*c - 36, b, c - 9) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 ]
		(?, 1)     f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
	start location:	f1
	leaf cost:	1

By chaining the transition f1(a, b, c) -> f0(a + 9*c - 36, b, c - 9) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 ] with all transitions in problem 11, the following new transition is obtained:
	f1(a, b, c) -> f0(a + 10*c - 45, b, c - 10) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 ]
We thus obtain the following problem:
12:	T:
		(1, 11)    f1(a, b, c) -> f0(a + 10*c - 45, b, c - 10) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 ]
		(?, 1)     f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
	start location:	f1
	leaf cost:	1

By chaining the transition f1(a, b, c) -> f0(a + 10*c - 45, b, c - 10) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 ] with all transitions in problem 12, the following new transition is obtained:
	f1(a, b, c) -> f0(a + 11*c - 55, b, c - 11) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 /\ a + 10*c - 45 >= 1 ]
We thus obtain the following problem:
13:	T:
		(1, 12)    f1(a, b, c) -> f0(a + 11*c - 55, b, c - 11) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 /\ a + 10*c - 45 >= 1 ]
		(?, 1)     f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
	start location:	f1
	leaf cost:	1

By chaining the transition f1(a, b, c) -> f0(a + 11*c - 55, b, c - 11) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 /\ a + 10*c - 45 >= 1 ] with all transitions in problem 13, the following new transition is obtained:
	f1(a, b, c) -> f0(a + 12*c - 66, b, c - 12) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 /\ a + 10*c - 45 >= 1 /\ a + 11*c - 55 >= 1 ]
We thus obtain the following problem:
14:	T:
		(1, 13)    f1(a, b, c) -> f0(a + 12*c - 66, b, c - 12) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 /\ a + 10*c - 45 >= 1 /\ a + 11*c - 55 >= 1 ]
		(?, 1)     f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
	start location:	f1
	leaf cost:	1

By chaining the transition f1(a, b, c) -> f0(a + 12*c - 66, b, c - 12) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 /\ a + 10*c - 45 >= 1 /\ a + 11*c - 55 >= 1 ] with all transitions in problem 14, the following new transition is obtained:
	f1(a, b, c) -> f0(a + 13*c - 78, b, c - 13) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 /\ a + 10*c - 45 >= 1 /\ a + 11*c - 55 >= 1 /\ a + 12*c - 66 >= 1 ]
We thus obtain the following problem:
15:	T:
		(1, 14)    f1(a, b, c) -> f0(a + 13*c - 78, b, c - 13) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 /\ a + 10*c - 45 >= 1 /\ a + 11*c - 55 >= 1 /\ a + 12*c - 66 >= 1 ]
		(?, 1)     f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
	start location:	f1
	leaf cost:	1

By chaining the transition f1(a, b, c) -> f0(a + 13*c - 78, b, c - 13) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 /\ a + 10*c - 45 >= 1 /\ a + 11*c - 55 >= 1 /\ a + 12*c - 66 >= 1 ] with all transitions in problem 15, the following new transition is obtained:
	f1(a, b, c) -> f0(a + 14*c - 91, b, c - 14) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 /\ a + 10*c - 45 >= 1 /\ a + 11*c - 55 >= 1 /\ a + 12*c - 66 >= 1 /\ a + 13*c - 78 >= 1 ]
We thus obtain the following problem:
16:	T:
		(1, 15)    f1(a, b, c) -> f0(a + 14*c - 91, b, c - 14) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 /\ a + 10*c - 45 >= 1 /\ a + 11*c - 55 >= 1 /\ a + 12*c - 66 >= 1 /\ a + 13*c - 78 >= 1 ]
		(?, 1)     f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
	start location:	f1
	leaf cost:	1

By chaining the transition f1(a, b, c) -> f0(a + 14*c - 91, b, c - 14) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 /\ a + 10*c - 45 >= 1 /\ a + 11*c - 55 >= 1 /\ a + 12*c - 66 >= 1 /\ a + 13*c - 78 >= 1 ] with all transitions in problem 16, the following new transition is obtained:
	f1(a, b, c) -> f0(a + 15*c - 105, b, c - 15) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 /\ a + 10*c - 45 >= 1 /\ a + 11*c - 55 >= 1 /\ a + 12*c - 66 >= 1 /\ a + 13*c - 78 >= 1 /\ a + 14*c - 91 >= 1 ]
We thus obtain the following problem:
17:	T:
		(1, 16)    f1(a, b, c) -> f0(a + 15*c - 105, b, c - 15) [ a >= 1 /\ a + c >= 1 /\ a + 2*c - 1 >= 1 /\ a + 3*c - 3 >= 1 /\ a + 4*c - 6 >= 1 /\ a + 5*c - 10 >= 1 /\ a + 6*c - 15 >= 1 /\ a + 7*c - 21 >= 1 /\ a + 8*c - 28 >= 1 /\ a + 9*c - 36 >= 1 /\ a + 10*c - 45 >= 1 /\ a + 11*c - 55 >= 1 /\ a + 12*c - 66 >= 1 /\ a + 13*c - 78 >= 1 /\ a + 14*c - 91 >= 1 ]
		(?, 1)     f0(a, b, c) -> f0(a + c, b, c - 1) [ a >= 1 ]
	start location:	f1
	leaf cost:	1

Complexity upper bound ?

Time: 2.763 sec (SMT: 2.641 sec)