YES(?, b + 1)

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

A polynomial rank function with
	Pol(eval) = V_2
	Pol(start) = V_2
orients all transitions weakly and the transition
	eval(a, b) -> eval(a - 1, b - 1) [ a >= 1 /\ b >= 1 ]
strictly and produces the following problem:
2:	T:
		(b, 1)    eval(a, b) -> eval(a - 1, b - 1) [ a >= 1 /\ b >= 1 ]
		(1, 1)    start(a, b) -> eval(a, b)
	start location:	start
	leaf cost:	0

Complexity upper bound b + 1

Time: 0.105 sec (SMT: 0.101 sec)