YES(?, a + b + 1)

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

A polynomial rank function with
	Pol(eval) = V_1 - V_2
	Pol(start) = V_1 - V_2
orients all transitions weakly and the transition
	eval(a, b) -> eval(a - 1, b + 1) [ a >= b + 1 ]
strictly and produces the following problem:
2:	T:
		(a + b, 1)    eval(a, b) -> eval(a - 1, b + 1) [ a >= b + 1 ]
		(1, 1)        start(a, b) -> eval(a, b)
	start location:	start
	leaf cost:	0

Complexity upper bound a + b + 1

Time: 0.063 sec (SMT: 0.060 sec)