YES(?, 3)

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

Repeatedly removing leaves of the complexity graph in problem 1 produces the following problem:
2:	T:
		(none)
	start location:	start
	leaf cost:	3

Complexity upper bound 3

Time: 0.034 sec (SMT: 0.033 sec)