Input TRS:
    1: is_empty(nil()) -> true()
    2: is_empty(cons(x,l)) -> false()
    3: hd(cons(x,l)) -> x
    4: tl(cons(x,l)) -> l
    5: append(l1,l2) -> ifappend(l1,l2,is_empty(l1))
    6: ifappend(l1,l2,true()) -> l2
    7: ifappend(l1,l2,false()) -> cons(hd(l1),append(tl(l1),l2))
Number of strict rules: 7
Direct Order(PosReal,>,Poly) ... failed.
Freezing ... failed.
Dependency Pairs:
   #1: #ifappend(l1,l2,false()) -> #hd(l1)
   #2: #ifappend(l1,l2,false()) -> #append(tl(l1),l2)
   #3: #ifappend(l1,l2,false()) -> #tl(l1)
   #4: #append(l1,l2) -> #ifappend(l1,l2,is_empty(l1))
   #5: #append(l1,l2) -> #is_empty(l1)
Number of SCCs: 1, DPs: 2, edges: 2
	SCC { #2 #4 }
Removing DPs: Order(PosReal,>,Sum)... Order(PosReal,>,Max)... QLPOpS... Order(PosReal,>,MaxSum)... succeeded.
    hd(x1)	weight: 0
#append(x1,x2)	weight: max{0, (/ 1 4) + x1}
#is_empty(x1)	weight: 0
ifappend(x1,x2,x3)	weight: 0
 false()	weight: (/ 1 4)
  true()	weight: (/ 1 8)
  #tl(x1)	weight: 0
append(x1,x2)	weight: 0
    tl(x1)	weight: max{0, (- (/ 1 8)) + x1}
   nil()	weight: (/ 1 8)
is_empty(x1)	weight: max{0, x1}
  #hd(x1)	weight: 0
  cons(x1,x2)	weight: max{0, (/ 1 8) + x1, (/ 1 4) + x2}
#ifappend(x1,x2,x3)	weight: max{0, (/ 1 4) + x1, (/ 1 4) + x3}
    Usable rules: { 1 2 4 }
    Removed DPs: #2
Number of SCCs: 0, DPs: 0, edges: 0
YES