YES(?, a + b + 2)

Initial complexity problem:
1:	T:
		(?, 1)    f300(a, b, c) -> f300(a + 1, b, c) [ b >= a + 1 ]
		(?, 1)    f300(a, b, c) -> f1(a, b, d) [ a >= b ]
		(1, 1)    f2(a, b, c) -> f300(a, b, c)
	start location:	f2
	leaf cost:	0

Repeatedly removing leaves of the complexity graph in problem 1 produces the following problem:
2:	T:
		(?, 1)    f300(a, b, c) -> f300(a + 1, b, c) [ b >= a + 1 ]
		(1, 1)    f2(a, b, c) -> f300(a, b, c)
	start location:	f2
	leaf cost:	1

A polynomial rank function with
	Pol(f300) = -V_1 + V_2
	Pol(f2) = -V_1 + V_2
orients all transitions weakly and the transition
	f300(a, b, c) -> f300(a + 1, b, c) [ b >= a + 1 ]
strictly and produces the following problem:
3:	T:
		(a + b, 1)    f300(a, b, c) -> f300(a + 1, b, c) [ b >= a + 1 ]
		(1, 1)        f2(a, b, c) -> f300(a, b, c)
	start location:	f2
	leaf cost:	1

Complexity upper bound a + b + 2

Time: 0.061 sec (SMT: 0.059 sec)