YES(?, 11)

Initial complexity problem:
1:	T:
		(1, 1)    f0(a, b, c, d) -> f8(0, b, c, d)
		(?, 1)    f8(a, b, c, d) -> f8(a + 1, b, c, d) [ 3 >= a ]
		(?, 1)    f8(a, b, c, d) -> f8(a + 1, a, a + 1, e) [ 3 >= a ]
		(?, 1)    f8(a, b, c, d) -> f23(a, b, c, d) [ a >= 4 /\ 0 >= e + 1 ]
		(?, 1)    f8(a, b, c, d) -> f23(a, b, c, d) [ a >= 4 ]
	start location:	f0
	leaf cost:	0

Repeatedly removing leaves of the complexity graph in problem 1 produces the following problem:
2:	T:
		(1, 1)    f0(a, b, c, d) -> f8(0, b, c, d)
		(?, 1)    f8(a, b, c, d) -> f8(a + 1, b, c, d) [ 3 >= a ]
		(?, 1)    f8(a, b, c, d) -> f8(a + 1, a, a + 1, e) [ 3 >= a ]
	start location:	f0
	leaf cost:	2

A polynomial rank function with
	Pol(f0) = 4
	Pol(f8) = -V_1 + 4
orients all transitions weakly and the transitions
	f8(a, b, c, d) -> f8(a + 1, b, c, d) [ 3 >= a ]
	f8(a, b, c, d) -> f8(a + 1, a, a + 1, e) [ 3 >= a ]
strictly and produces the following problem:
3:	T:
		(1, 1)    f0(a, b, c, d) -> f8(0, b, c, d)
		(4, 1)    f8(a, b, c, d) -> f8(a + 1, b, c, d) [ 3 >= a ]
		(4, 1)    f8(a, b, c, d) -> f8(a + 1, a, a + 1, e) [ 3 >= a ]
	start location:	f0
	leaf cost:	2

Complexity upper bound 11

Time: 0.215 sec (SMT: 0.204 sec)