YES(?, 12)

Initial complexity problem:
1:	T:
		(1, 1)    f0(a, b) -> f6(c, 0)
		(?, 1)    f6(a, b) -> f6(a, b + 1) [ 9 >= b ]
		(?, 1)    f6(a, b) -> f15(a, b) [ b >= 10 ]
	start location:	f0
	leaf cost:	0

Repeatedly removing leaves of the complexity graph in problem 1 produces the following problem:
2:	T:
		(1, 1)    f0(a, b) -> f6(c, 0)
		(?, 1)    f6(a, b) -> f6(a, b + 1) [ 9 >= b ]
	start location:	f0
	leaf cost:	1

A polynomial rank function with
	Pol(f0) = 10
	Pol(f6) = -V_2 + 10
orients all transitions weakly and the transition
	f6(a, b) -> f6(a, b + 1) [ 9 >= b ]
strictly and produces the following problem:
3:	T:
		(1, 1)     f0(a, b) -> f6(c, 0)
		(10, 1)    f6(a, b) -> f6(a, b + 1) [ 9 >= b ]
	start location:	f0
	leaf cost:	1

Complexity upper bound 12

Time: 0.070 sec (SMT: 0.068 sec)