MAYBE

Initial complexity problem:
1:	T:
		(1, 1)    f0(a) -> f1(a)
		(?, 1)    f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

By chaining the transition f0(a) -> f1(a) with all transitions in problem 1, the following new transition is obtained:
	f0(a) -> f1(a + 1000) [ a + 999 >= 0 ]
We thus obtain the following problem:
2:	T:
		(1, 2)    f0(a) -> f1(a + 1000) [ a + 999 >= 0 ]
		(?, 1)    f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

By chaining the transition f0(a) -> f1(a + 1000) [ a + 999 >= 0 ] with all transitions in problem 2, the following new transition is obtained:
	f0(a) -> f1(a + 2000) [ a + 999 >= 0 /\ a + 1999 >= 0 ]
We thus obtain the following problem:
3:	T:
		(1, 3)    f0(a) -> f1(a + 2000) [ a + 999 >= 0 /\ a + 1999 >= 0 ]
		(?, 1)    f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

By chaining the transition f0(a) -> f1(a + 2000) [ a + 999 >= 0 /\ a + 1999 >= 0 ] with all transitions in problem 3, the following new transition is obtained:
	f0(a) -> f1(a + 3000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 ]
We thus obtain the following problem:
4:	T:
		(1, 4)    f0(a) -> f1(a + 3000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 ]
		(?, 1)    f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

By chaining the transition f0(a) -> f1(a + 3000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 ] with all transitions in problem 4, the following new transition is obtained:
	f0(a) -> f1(a + 4000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 ]
We thus obtain the following problem:
5:	T:
		(1, 5)    f0(a) -> f1(a + 4000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 ]
		(?, 1)    f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

By chaining the transition f0(a) -> f1(a + 4000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 ] with all transitions in problem 5, the following new transition is obtained:
	f0(a) -> f1(a + 5000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 ]
We thus obtain the following problem:
6:	T:
		(1, 6)    f0(a) -> f1(a + 5000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 ]
		(?, 1)    f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

By chaining the transition f0(a) -> f1(a + 5000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 ] with all transitions in problem 6, the following new transition is obtained:
	f0(a) -> f1(a + 6000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 ]
We thus obtain the following problem:
7:	T:
		(1, 7)    f0(a) -> f1(a + 6000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 ]
		(?, 1)    f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

By chaining the transition f0(a) -> f1(a + 6000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 ] with all transitions in problem 7, the following new transition is obtained:
	f0(a) -> f1(a + 7000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 ]
We thus obtain the following problem:
8:	T:
		(1, 8)    f0(a) -> f1(a + 7000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 ]
		(?, 1)    f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

By chaining the transition f0(a) -> f1(a + 7000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 ] with all transitions in problem 8, the following new transition is obtained:
	f0(a) -> f1(a + 8000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 ]
We thus obtain the following problem:
9:	T:
		(1, 9)    f0(a) -> f1(a + 8000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 ]
		(?, 1)    f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

By chaining the transition f0(a) -> f1(a + 8000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 ] with all transitions in problem 9, the following new transition is obtained:
	f0(a) -> f1(a + 9000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 ]
We thus obtain the following problem:
10:	T:
		(1, 10)    f0(a) -> f1(a + 9000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 ]
		(?, 1)     f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

By chaining the transition f0(a) -> f1(a + 9000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 ] with all transitions in problem 10, the following new transition is obtained:
	f0(a) -> f1(a + 10000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 ]
We thus obtain the following problem:
11:	T:
		(1, 11)    f0(a) -> f1(a + 10000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 ]
		(?, 1)     f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

By chaining the transition f0(a) -> f1(a + 10000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 ] with all transitions in problem 11, the following new transition is obtained:
	f0(a) -> f1(a + 11000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 /\ a + 10999 >= 0 ]
We thus obtain the following problem:
12:	T:
		(1, 12)    f0(a) -> f1(a + 11000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 /\ a + 10999 >= 0 ]
		(?, 1)     f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

By chaining the transition f0(a) -> f1(a + 11000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 /\ a + 10999 >= 0 ] with all transitions in problem 12, the following new transition is obtained:
	f0(a) -> f1(a + 12000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 /\ a + 10999 >= 0 /\ a + 11999 >= 0 ]
We thus obtain the following problem:
13:	T:
		(1, 13)    f0(a) -> f1(a + 12000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 /\ a + 10999 >= 0 /\ a + 11999 >= 0 ]
		(?, 1)     f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

By chaining the transition f0(a) -> f1(a + 12000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 /\ a + 10999 >= 0 /\ a + 11999 >= 0 ] with all transitions in problem 13, the following new transition is obtained:
	f0(a) -> f1(a + 13000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 /\ a + 10999 >= 0 /\ a + 11999 >= 0 /\ a + 12999 >= 0 ]
We thus obtain the following problem:
14:	T:
		(1, 14)    f0(a) -> f1(a + 13000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 /\ a + 10999 >= 0 /\ a + 11999 >= 0 /\ a + 12999 >= 0 ]
		(?, 1)     f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

By chaining the transition f0(a) -> f1(a + 13000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 /\ a + 10999 >= 0 /\ a + 11999 >= 0 /\ a + 12999 >= 0 ] with all transitions in problem 14, the following new transition is obtained:
	f0(a) -> f1(a + 14000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 /\ a + 10999 >= 0 /\ a + 11999 >= 0 /\ a + 12999 >= 0 /\ a + 13999 >= 0 ]
We thus obtain the following problem:
15:	T:
		(1, 15)    f0(a) -> f1(a + 14000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 /\ a + 10999 >= 0 /\ a + 11999 >= 0 /\ a + 12999 >= 0 /\ a + 13999 >= 0 ]
		(?, 1)     f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

By chaining the transition f0(a) -> f1(a + 14000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 /\ a + 10999 >= 0 /\ a + 11999 >= 0 /\ a + 12999 >= 0 /\ a + 13999 >= 0 ] with all transitions in problem 15, the following new transition is obtained:
	f0(a) -> f1(a + 15000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 /\ a + 10999 >= 0 /\ a + 11999 >= 0 /\ a + 12999 >= 0 /\ a + 13999 >= 0 /\ a + 14999 >= 0 ]
We thus obtain the following problem:
16:	T:
		(1, 16)    f0(a) -> f1(a + 15000) [ a + 999 >= 0 /\ a + 1999 >= 0 /\ a + 2999 >= 0 /\ a + 3999 >= 0 /\ a + 4999 >= 0 /\ a + 5999 >= 0 /\ a + 6999 >= 0 /\ a + 7999 >= 0 /\ a + 8999 >= 0 /\ a + 9999 >= 0 /\ a + 10999 >= 0 /\ a + 11999 >= 0 /\ a + 12999 >= 0 /\ a + 13999 >= 0 /\ a + 14999 >= 0 ]
		(?, 1)     f1(a) -> f1(a + 1000) [ a + 999 >= 0 ]
	start location:	f0
	leaf cost:	0

Complexity upper bound ?

Time: 1.339 sec (SMT: 1.270 sec)