YES(?, a + 2)

Initial complexity problem:
1:	T:
		(1, 1)    start(a) -> a(a) [ a >= 1 ]
		(1, 1)    start(a) -> a(100) [ a = 100 ]
		(?, 1)    a(a) -> a(a - 1) [ a >= 1 ]
	start location:	start
	leaf cost:	0

A polynomial rank function with
	Pol(start) = V_1
	Pol(a) = V_1
orients all transitions weakly and the transition
	a(a) -> a(a - 1) [ a >= 1 ]
strictly and produces the following problem:
2:	T:
		(1, 1)    start(a) -> a(a) [ a >= 1 ]
		(1, 1)    start(a) -> a(100) [ a = 100 ]
		(a, 1)    a(a) -> a(a - 1) [ a >= 1 ]
	start location:	start
	leaf cost:	0

Complexity upper bound a + 2

Time: 0.071 sec (SMT: 0.068 sec)