MAYBE

Initial complexity problem:
1:	T:
		(Comp: ?, Cost: 1)    f0(Ar_0) -> Com_1(f4(Fresh_0))
		(Comp: ?, Cost: 1)    f4(Ar_0) -> Com_1(f4(Ar_0 + 1)) [ 3 >= Ar_0 /\ Ar_0 >= 1 ]
		(Comp: ?, Cost: 1)    f4(Ar_0) -> Com_1(f4(1)) [ 0 >= Ar_0 /\ 3 >= Ar_0 ]
		(Comp: ?, Cost: 1)    f4(Ar_0) -> Com_1(f12(Ar_0)) [ Ar_0 >= 4 ]
		(Comp: 1, Cost: 0)    koat_start(Ar_0) -> Com_1(f0(Ar_0)) [ 0 <= 0 ]
	start location:	koat_start
	leaf cost:	0

Repeatedly propagating knowledge in problem 1 produces the following problem:
2:	T:
		(Comp: 1, Cost: 1)    f0(Ar_0) -> Com_1(f4(Fresh_0))
		(Comp: ?, Cost: 1)    f4(Ar_0) -> Com_1(f4(Ar_0 + 1)) [ 3 >= Ar_0 /\ Ar_0 >= 1 ]
		(Comp: 1, Cost: 1)    f4(Ar_0) -> Com_1(f4(1)) [ 0 >= Ar_0 /\ 3 >= Ar_0 ]
		(Comp: ?, Cost: 1)    f4(Ar_0) -> Com_1(f12(Ar_0)) [ Ar_0 >= 4 ]
		(Comp: 1, Cost: 0)    koat_start(Ar_0) -> Com_1(f0(Ar_0)) [ 0 <= 0 ]
	start location:	koat_start
	leaf cost:	0

A polynomial rank function with
	Pol(f0) = 1
	Pol(f4) = 1
	Pol(f12) = 0
	Pol(koat_start) = 1
orients all transitions weakly and the transition
	f4(Ar_0) -> Com_1(f12(Ar_0)) [ Ar_0 >= 4 ]
strictly and produces the following problem:
3:	T:
		(Comp: 1, Cost: 1)    f0(Ar_0) -> Com_1(f4(Fresh_0))
		(Comp: ?, Cost: 1)    f4(Ar_0) -> Com_1(f4(Ar_0 + 1)) [ 3 >= Ar_0 /\ Ar_0 >= 1 ]
		(Comp: 1, Cost: 1)    f4(Ar_0) -> Com_1(f4(1)) [ 0 >= Ar_0 /\ 3 >= Ar_0 ]
		(Comp: 1, Cost: 1)    f4(Ar_0) -> Com_1(f12(Ar_0)) [ Ar_0 >= 4 ]
		(Comp: 1, Cost: 0)    koat_start(Ar_0) -> Com_1(f0(Ar_0)) [ 0 <= 0 ]
	start location:	koat_start
	leaf cost:	0

Complexity upper bound ?

Time: 0.581 sec (SMT: 0.552 sec)