MAYBE

Initial complexity problem:
1:	T:
		(1, 1)    f0(a) -> f1(a)
		(?, 1)    f1(a) -> f1(0) [ a >= 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(0) [ a >= 0 ]
We thus obtain the following problem:
2:	T:
		(1, 2)    f0(a) -> f1(0) [ a >= 0 ]
		(?, 1)    f1(a) -> f1(0) [ a >= 0 ]
	start location:	f0
	leaf cost:	0

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

Complexity upper bound ?

Time: 0.114 sec (SMT: 0.105 sec)