YES(?, a + 1)

Initial complexity problem:
1:	T:
		(1, 1)    f3(a) -> f1(a) [ a >= 0 ]
		(?, 1)    f1(a) -> f1(a - 1) [ a >= 1 ]
	start location:	f3
	leaf cost:	0

A polynomial rank function with
	Pol(f3) = V_1
	Pol(f1) = V_1
orients all transitions weakly and the transition
	f1(a) -> f1(a - 1) [ a >= 1 ]
strictly and produces the following problem:
2:	T:
		(1, 1)    f3(a) -> f1(a) [ a >= 0 ]
		(a, 1)    f1(a) -> f1(a - 1) [ a >= 1 ]
	start location:	f3
	leaf cost:	0

Complexity upper bound a + 1

Time: 0.065 sec (SMT: 0.062 sec)