MAYBE

Initial complexity problem:
1:	T:
		(Comp: ?, Cost: 1)    f2(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f2(Ar_0 + 1, Ar_1 + 1, Ar_2 - 1, Ar_3))
		(Comp: ?, Cost: 1)    f1(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f2(Ar_0, Ar_1, Ar_2, Ar_3)) [ Ar_0 >= Ar_2 /\ Ar_1 >= Ar_0 /\ Ar_2 >= Ar_1 ]
		(Comp: ?, Cost: 1)    f1(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f300(Ar_0, Ar_1, Ar_2, Fresh_2)) [ Ar_2 >= Ar_0 + 1 /\ Ar_1 >= Ar_0 /\ Ar_2 >= Ar_1 ]
		(Comp: ?, Cost: 1)    f1(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f300(Ar_0, Ar_1, Ar_2, Fresh_1)) [ Ar_1 >= Ar_0 /\ Ar_1 >= Ar_2 + 1 ]
		(Comp: ?, Cost: 1)    f1(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f300(Ar_0, Ar_1, Ar_2, Fresh_0)) [ Ar_0 >= Ar_1 + 1 ]
		(Comp: 1, Cost: 0)    koat_start(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f1(Ar_0, Ar_1, Ar_2, Ar_3)) [ 0 <= 0 ]
	start location:	koat_start
	leaf cost:	0

Repeatedly propagating knowledge in problem 1 produces the following problem:
2:	T:
		(Comp: ?, Cost: 1)    f2(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f2(Ar_0 + 1, Ar_1 + 1, Ar_2 - 1, Ar_3))
		(Comp: 1, Cost: 1)    f1(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f2(Ar_0, Ar_1, Ar_2, Ar_3)) [ Ar_0 >= Ar_2 /\ Ar_1 >= Ar_0 /\ Ar_2 >= Ar_1 ]
		(Comp: 1, Cost: 1)    f1(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f300(Ar_0, Ar_1, Ar_2, Fresh_2)) [ Ar_2 >= Ar_0 + 1 /\ Ar_1 >= Ar_0 /\ Ar_2 >= Ar_1 ]
		(Comp: 1, Cost: 1)    f1(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f300(Ar_0, Ar_1, Ar_2, Fresh_1)) [ Ar_1 >= Ar_0 /\ Ar_1 >= Ar_2 + 1 ]
		(Comp: 1, Cost: 1)    f1(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f300(Ar_0, Ar_1, Ar_2, Fresh_0)) [ Ar_0 >= Ar_1 + 1 ]
		(Comp: 1, Cost: 0)    koat_start(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f1(Ar_0, Ar_1, Ar_2, Ar_3)) [ 0 <= 0 ]
	start location:	koat_start
	leaf cost:	0

Applied AI with 'oct' on problem 2 to obtain the following invariants:
  For symbol f2: X_2 - X_3 >= 0 /\ X_1 - X_3 >= 0 /\ X_1 - X_2 >= 0 /\ -X_1 + X_2 >= 0


This yielded the following problem:
3:	T:
		(Comp: 1, Cost: 0)    koat_start(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f1(Ar_0, Ar_1, Ar_2, Ar_3)) [ 0 <= 0 ]
		(Comp: 1, Cost: 1)    f1(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f300(Ar_0, Ar_1, Ar_2, Fresh_0)) [ Ar_0 >= Ar_1 + 1 ]
		(Comp: 1, Cost: 1)    f1(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f300(Ar_0, Ar_1, Ar_2, Fresh_1)) [ Ar_1 >= Ar_0 /\ Ar_1 >= Ar_2 + 1 ]
		(Comp: 1, Cost: 1)    f1(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f300(Ar_0, Ar_1, Ar_2, Fresh_2)) [ Ar_2 >= Ar_0 + 1 /\ Ar_1 >= Ar_0 /\ Ar_2 >= Ar_1 ]
		(Comp: 1, Cost: 1)    f1(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f2(Ar_0, Ar_1, Ar_2, Ar_3)) [ Ar_0 >= Ar_2 /\ Ar_1 >= Ar_0 /\ Ar_2 >= Ar_1 ]
		(Comp: ?, Cost: 1)    f2(Ar_0, Ar_1, Ar_2, Ar_3) -> Com_1(f2(Ar_0 + 1, Ar_1 + 1, Ar_2 - 1, Ar_3)) [ Ar_1 - Ar_2 >= 0 /\ Ar_0 - Ar_2 >= 0 /\ Ar_0 - Ar_1 >= 0 /\ -Ar_0 + Ar_1 >= 0 ]
	start location:	koat_start
	leaf cost:	0

Complexity upper bound ?

Time: 1.222 sec (SMT: 1.177 sec)