MAYBE

Initial complexity problem:
1:	T:
		(Comp: ?, Cost: 1)    f0(Ar_0, Ar_1, Ar_2, Ar_3, Ar_4) -> Com_1(f2(Ar_0, Fresh_14, Ar_2, Ar_3, Ar_4)) [ 0 >= Ar_0 ]
		(Comp: ?, Cost: 1)    f0(Ar_0, Ar_1, Ar_2, Ar_3, Ar_4) -> Com_1(f0(3*Ar_0 + 1, Ar_1, Fresh_11, Fresh_12, Fresh_13)) [ Ar_0 >= 1 /\ Ar_0 >= 2*Fresh_13 + 1 /\ 3*Ar_0 >= 3*Fresh_11 /\ 3*Fresh_11 >= 3*Ar_0 /\ Fresh_11 >= 2*Fresh_13 + 1 /\ Fresh_11 >= 1 ]
		(Comp: ?, Cost: 1)    f0(Ar_0, Ar_1, Ar_2, Ar_3, Ar_4) -> Com_1(f0(3*Ar_0 + 1, Ar_1, Fresh_8, Fresh_9, Fresh_10)) [ Ar_0 >= 1 /\ Ar_0 >= 2*Fresh_10 + 1 /\ 3*Ar_0 >= 3*Fresh_8 /\ 3*Fresh_8 >= 3*Ar_0 /\ 2*Fresh_10 >= Fresh_8 + 1 /\ Fresh_8 >= 1 ]
		(Comp: ?, Cost: 1)    f0(Ar_0, Ar_1, Ar_2, Ar_3, Ar_4) -> Com_1(f0(3*Ar_0 + 1, Ar_1, Fresh_5, Fresh_6, Fresh_7)) [ Ar_0 >= 1 /\ 2*Fresh_7 >= Ar_0 + 1 /\ 3*Ar_0 >= 3*Fresh_5 /\ 3*Fresh_5 >= 3*Ar_0 /\ Fresh_5 >= 2*Fresh_7 + 1 /\ Fresh_5 >= 1 ]
		(Comp: ?, Cost: 1)    f0(Ar_0, Ar_1, Ar_2, Ar_3, Ar_4) -> Com_1(f0(3*Ar_0 + 1, Ar_1, Fresh_2, Fresh_3, Fresh_4)) [ Ar_0 >= 1 /\ 2*Fresh_4 >= Ar_0 + 1 /\ 3*Ar_0 >= 3*Fresh_2 /\ 3*Fresh_2 >= 3*Ar_0 /\ 2*Fresh_4 >= Fresh_2 + 1 /\ Fresh_2 >= 1 ]
		(Comp: ?, Cost: 1)    f0(Ar_0, Ar_1, Ar_2, Ar_3, Ar_4) -> Com_1(f0(Fresh_0, Ar_1, Ar_2, Fresh_1, Fresh_0)) [ 2*Fresh_0 >= 1 /\ G >= 1 /\ Ar_0 = 2*Fresh_0 ]
		(Comp: ?, Cost: 1)    f1(Ar_0, Ar_1, Ar_2, Ar_3, Ar_4) -> Com_1(f0(Ar_0, Ar_1, Ar_2, Ar_3, Ar_4))
		(Comp: 1, Cost: 0)    koat_start(Ar_0, Ar_1, Ar_2, Ar_3, Ar_4) -> Com_1(f1(Ar_0, Ar_1, Ar_2, Ar_3, Ar_4)) [ 0 <= 0 ]
	start location:	koat_start
	leaf cost:	0

Slicing away variables that do not contribute to conditions from problem 1 leaves variables [Ar_0].
We thus obtain the following problem:
2:	T:
		(Comp: 1, Cost: 0)    koat_start(Ar_0) -> Com_1(f1(Ar_0)) [ 0 <= 0 ]
		(Comp: ?, Cost: 1)    f1(Ar_0) -> Com_1(f0(Ar_0))
		(Comp: ?, Cost: 1)    f0(Ar_0) -> Com_1(f0(Fresh_0)) [ 2*Fresh_0 >= 1 /\ G >= 1 /\ Ar_0 = 2*Fresh_0 ]
		(Comp: ?, Cost: 1)    f0(Ar_0) -> Com_1(f0(3*Ar_0 + 1)) [ Ar_0 >= 1 /\ 2*Fresh_4 >= Ar_0 + 1 /\ 3*Ar_0 >= 3*Fresh_2 /\ 3*Fresh_2 >= 3*Ar_0 /\ 2*Fresh_4 >= Fresh_2 + 1 /\ Fresh_2 >= 1 ]
		(Comp: ?, Cost: 1)    f0(Ar_0) -> Com_1(f0(3*Ar_0 + 1)) [ Ar_0 >= 1 /\ 2*Fresh_7 >= Ar_0 + 1 /\ 3*Ar_0 >= 3*Fresh_5 /\ 3*Fresh_5 >= 3*Ar_0 /\ Fresh_5 >= 2*Fresh_7 + 1 /\ Fresh_5 >= 1 ]
		(Comp: ?, Cost: 1)    f0(Ar_0) -> Com_1(f0(3*Ar_0 + 1)) [ Ar_0 >= 1 /\ Ar_0 >= 2*Fresh_10 + 1 /\ 3*Ar_0 >= 3*Fresh_8 /\ 3*Fresh_8 >= 3*Ar_0 /\ 2*Fresh_10 >= Fresh_8 + 1 /\ Fresh_8 >= 1 ]
		(Comp: ?, Cost: 1)    f0(Ar_0) -> Com_1(f0(3*Ar_0 + 1)) [ Ar_0 >= 1 /\ Ar_0 >= 2*Fresh_13 + 1 /\ 3*Ar_0 >= 3*Fresh_11 /\ 3*Fresh_11 >= 3*Ar_0 /\ Fresh_11 >= 2*Fresh_13 + 1 /\ Fresh_11 >= 1 ]
		(Comp: ?, Cost: 1)    f0(Ar_0) -> Com_1(f2(Ar_0)) [ 0 >= Ar_0 ]
	start location:	koat_start
	leaf cost:	0

Testing for reachability in the complexity graph removes the following transitions from problem 2:
	f0(Ar_0) -> Com_1(f0(3*Ar_0 + 1)) [ Ar_0 >= 1 /\ 2*Fresh_7 >= Ar_0 + 1 /\ 3*Ar_0 >= 3*Fresh_5 /\ 3*Fresh_5 >= 3*Ar_0 /\ Fresh_5 >= 2*Fresh_7 + 1 /\ Fresh_5 >= 1 ]
	f0(Ar_0) -> Com_1(f0(3*Ar_0 + 1)) [ Ar_0 >= 1 /\ Ar_0 >= 2*Fresh_10 + 1 /\ 3*Ar_0 >= 3*Fresh_8 /\ 3*Fresh_8 >= 3*Ar_0 /\ 2*Fresh_10 >= Fresh_8 + 1 /\ Fresh_8 >= 1 ]
We thus obtain the following problem:
3:	T:
		(Comp: ?, Cost: 1)    f0(Ar_0) -> Com_1(f2(Ar_0)) [ 0 >= Ar_0 ]
		(Comp: ?, Cost: 1)    f0(Ar_0) -> Com_1(f0(3*Ar_0 + 1)) [ Ar_0 >= 1 /\ Ar_0 >= 2*Fresh_13 + 1 /\ 3*Ar_0 >= 3*Fresh_11 /\ 3*Fresh_11 >= 3*Ar_0 /\ Fresh_11 >= 2*Fresh_13 + 1 /\ Fresh_11 >= 1 ]
		(Comp: ?, Cost: 1)    f0(Ar_0) -> Com_1(f0(3*Ar_0 + 1)) [ Ar_0 >= 1 /\ 2*Fresh_4 >= Ar_0 + 1 /\ 3*Ar_0 >= 3*Fresh_2 /\ 3*Fresh_2 >= 3*Ar_0 /\ 2*Fresh_4 >= Fresh_2 + 1 /\ Fresh_2 >= 1 ]
		(Comp: ?, Cost: 1)    f0(Ar_0) -> Com_1(f0(Fresh_0)) [ 2*Fresh_0 >= 1 /\ G >= 1 /\ Ar_0 = 2*Fresh_0 ]
		(Comp: ?, Cost: 1)    f1(Ar_0) -> Com_1(f0(Ar_0))
		(Comp: 1, Cost: 0)    koat_start(Ar_0) -> Com_1(f1(Ar_0)) [ 0 <= 0 ]
	start location:	koat_start
	leaf cost:	0

Repeatedly propagating knowledge in problem 3 produces the following problem:
4:	T:
		(Comp: 1, Cost: 1)    f0(Ar_0) -> Com_1(f2(Ar_0)) [ 0 >= Ar_0 ]
		(Comp: ?, Cost: 1)    f0(Ar_0) -> Com_1(f0(3*Ar_0 + 1)) [ Ar_0 >= 1 /\ Ar_0 >= 2*Fresh_13 + 1 /\ 3*Ar_0 >= 3*Fresh_11 /\ 3*Fresh_11 >= 3*Ar_0 /\ Fresh_11 >= 2*Fresh_13 + 1 /\ Fresh_11 >= 1 ]
		(Comp: ?, Cost: 1)    f0(Ar_0) -> Com_1(f0(3*Ar_0 + 1)) [ Ar_0 >= 1 /\ 2*Fresh_4 >= Ar_0 + 1 /\ 3*Ar_0 >= 3*Fresh_2 /\ 3*Fresh_2 >= 3*Ar_0 /\ 2*Fresh_4 >= Fresh_2 + 1 /\ Fresh_2 >= 1 ]
		(Comp: ?, Cost: 1)    f0(Ar_0) -> Com_1(f0(Fresh_0)) [ 2*Fresh_0 >= 1 /\ G >= 1 /\ Ar_0 = 2*Fresh_0 ]
		(Comp: 1, Cost: 1)    f1(Ar_0) -> Com_1(f0(Ar_0))
		(Comp: 1, Cost: 0)    koat_start(Ar_0) -> Com_1(f1(Ar_0)) [ 0 <= 0 ]
	start location:	koat_start
	leaf cost:	0

Complexity upper bound ?

Time: 1.605 sec (SMT: 1.561 sec)