YES
We show the termination of the TRS R:

  app(nil(),k) -> k
  app(l,nil()) -> l
  app(cons(x,l),k) -> cons(x,app(l,k))
  sum(cons(x,nil())) -> cons(x,nil())
  sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l))
  sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k)))))
  sum(plus(cons(|0|(),x),cons(y,l))) -> pred(sum(cons(s(x),cons(y,l))))
  pred(cons(s(x),nil())) -> cons(x,nil())
  plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y)))))
  plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x))
  plus(zero(),y) -> y
  plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y))))
  id(x) -> x
  if(true(),x,y) -> x
  if(false(),x,y) -> y
  not(x) -> if(x,false(),true())
  gt(s(x),zero()) -> true()
  gt(zero(),y) -> false()
  gt(s(x),s(y)) -> gt(x,y)


-- SCC decomposition.

Consider the dependency pair problem (P, R), where P consists of

p1: app#(cons(x,l),k) -> app#(l,k)
p2: sum#(cons(x,cons(y,l))) -> sum#(cons(plus(x,y),l))
p3: sum#(cons(x,cons(y,l))) -> plus#(x,y)
p4: sum#(app(l,cons(x,cons(y,k)))) -> sum#(app(l,sum(cons(x,cons(y,k)))))
p5: sum#(app(l,cons(x,cons(y,k)))) -> app#(l,sum(cons(x,cons(y,k))))
p6: sum#(app(l,cons(x,cons(y,k)))) -> sum#(cons(x,cons(y,k)))
p7: sum#(plus(cons(|0|(),x),cons(y,l))) -> pred#(sum(cons(s(x),cons(y,l))))
p8: sum#(plus(cons(|0|(),x),cons(y,l))) -> sum#(cons(s(x),cons(y,l)))
p9: plus#(s(x),s(y)) -> plus#(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y)))
p10: plus#(s(x),s(y)) -> if#(gt(x,y),x,y)
p11: plus#(s(x),s(y)) -> gt#(x,y)
p12: plus#(s(x),s(y)) -> if#(not(gt(x,y)),id(x),id(y))
p13: plus#(s(x),s(y)) -> not#(gt(x,y))
p14: plus#(s(x),s(y)) -> id#(x)
p15: plus#(s(x),s(y)) -> id#(y)
p16: plus#(s(x),x) -> plus#(if(gt(x,x),id(x),id(x)),s(x))
p17: plus#(s(x),x) -> if#(gt(x,x),id(x),id(x))
p18: plus#(s(x),x) -> gt#(x,x)
p19: plus#(s(x),x) -> id#(x)
p20: plus#(id(x),s(y)) -> plus#(x,if(gt(s(y),y),y,s(y)))
p21: plus#(id(x),s(y)) -> if#(gt(s(y),y),y,s(y))
p22: plus#(id(x),s(y)) -> gt#(s(y),y)
p23: not#(x) -> if#(x,false(),true())
p24: gt#(s(x),s(y)) -> gt#(x,y)

and R consists of:

r1: app(nil(),k) -> k
r2: app(l,nil()) -> l
r3: app(cons(x,l),k) -> cons(x,app(l,k))
r4: sum(cons(x,nil())) -> cons(x,nil())
r5: sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l))
r6: sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k)))))
r7: sum(plus(cons(|0|(),x),cons(y,l))) -> pred(sum(cons(s(x),cons(y,l))))
r8: pred(cons(s(x),nil())) -> cons(x,nil())
r9: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y)))))
r10: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x))
r11: plus(zero(),y) -> y
r12: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y))))
r13: id(x) -> x
r14: if(true(),x,y) -> x
r15: if(false(),x,y) -> y
r16: not(x) -> if(x,false(),true())
r17: gt(s(x),zero()) -> true()
r18: gt(zero(),y) -> false()
r19: gt(s(x),s(y)) -> gt(x,y)

The estimated dependency graph contains the following SCCs:

  {p4}
  {p1}
  {p2}
  {p9, p16, p20}
  {p24}


-- Reduction pair.

Consider the dependency pair problem (P, R), where P consists of

p1: sum#(app(l,cons(x,cons(y,k)))) -> sum#(app(l,sum(cons(x,cons(y,k)))))

and R consists of:

r1: app(nil(),k) -> k
r2: app(l,nil()) -> l
r3: app(cons(x,l),k) -> cons(x,app(l,k))
r4: sum(cons(x,nil())) -> cons(x,nil())
r5: sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l))
r6: sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k)))))
r7: sum(plus(cons(|0|(),x),cons(y,l))) -> pred(sum(cons(s(x),cons(y,l))))
r8: pred(cons(s(x),nil())) -> cons(x,nil())
r9: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y)))))
r10: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x))
r11: plus(zero(),y) -> y
r12: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y))))
r13: id(x) -> x
r14: if(true(),x,y) -> x
r15: if(false(),x,y) -> y
r16: not(x) -> if(x,false(),true())
r17: gt(s(x),zero()) -> true()
r18: gt(zero(),y) -> false()
r19: gt(s(x),s(y)) -> gt(x,y)

The set of usable rules consists of

  r1, r2, r3, r4, r5, r9, r10, r11, r12, r13, r14, r15, r16, r17, r18, r19

Take the reduction pair:

  generalized weighted path order (>=MG, >G)
  
    base order 1:
  
      matrix interpretation with standard point-wise order:
      
        carrier: N^1
        order: standard order
        interpretations:
          sum#_A(x1) = x1
          app_A(x1,x2) = x1 + x2 + 6
          cons_A(x1,x2) = 5
          sum_A(x1) = 5
          nil_A() = 1
          plus_A(x1,x2) = x2 + 4
          s_A(x1) = 0
          if_A(x1,x2,x3) = x2 + x3 + 5
          gt_A(x1,x2) = 2
          not_A(x1) = x1 + 8
          id_A(x1) = x1 + 3
          zero_A() = 2
          true_A() = 1
          false_A() = 1
  
    base order 2:
  
      marked-algebra reduction triple (>=A, >=A!, >A!):
      
        max/plus interpretation on natural numbers:
        
          sum#_A(x1) = max{0, x1 - 16}
          app_A(x1,x2) = max{15, x1 + 3, x2}
          cons_A(x1,x2) = max{11, x1 - 57, x2}
          sum_A(x1) = max{14, x1}
          nil_A = 2
          plus_A(x1,x2) = max{56, x1, x2}
          s_A(x1) = max{4, x1}
          if_A(x1,x2,x3) = max{56, x1 - 57, x2, x3}
          gt_A(x1,x2) = max{33, x1 - 5, x2 - 5}
          not_A(x1) = max{56, x1}
          id_A(x1) = max{2, x1}
          zero_A = 4
          true_A = 1
          false_A = 1
          sum#!_A(x1) = x1 + 59
          app!_A(x1,x2) = max{x1 + 139, x2 + 64}
          cons!_A(x1,x2) = max{68, x2 + 66}
          sum!_A(x1) = 69
          nil!_A = 67
          plus!_A(x1,x2) = max{78, x1 + 22, x2 - 5}
          s!_A(x1) = max{7, x1 - 31}
          if!_A(x1,x2,x3) = max{78, x2 - 8, x3 - 32}
          gt!_A(x1,x2) = 2
          not!_A(x1) = max{79, x1 - 35}
          id!_A(x1) = max{3, x1 - 30}
          zero!_A = 9
          true!_A = 8
          false!_A = 1
  
    partial status:
  
      pi(sum#) = [1]
      pi(app) = [2]
      pi(cons) = []
      pi(sum) = []
      pi(nil) = []
      pi(plus) = []
      pi(s) = []
      pi(if) = []
      pi(gt) = []
      pi(not) = [1]
      pi(id) = [1]
      pi(zero) = []
      pi(true) = []
      pi(false) = []

The following rules are removed:

  p1

Then no dependency pair remains.

-- Reduction pair.

Consider the dependency pair problem (P, R), where P consists of

p1: app#(cons(x,l),k) -> app#(l,k)

and R consists of:

r1: app(nil(),k) -> k
r2: app(l,nil()) -> l
r3: app(cons(x,l),k) -> cons(x,app(l,k))
r4: sum(cons(x,nil())) -> cons(x,nil())
r5: sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l))
r6: sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k)))))
r7: sum(plus(cons(|0|(),x),cons(y,l))) -> pred(sum(cons(s(x),cons(y,l))))
r8: pred(cons(s(x),nil())) -> cons(x,nil())
r9: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y)))))
r10: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x))
r11: plus(zero(),y) -> y
r12: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y))))
r13: id(x) -> x
r14: if(true(),x,y) -> x
r15: if(false(),x,y) -> y
r16: not(x) -> if(x,false(),true())
r17: gt(s(x),zero()) -> true()
r18: gt(zero(),y) -> false()
r19: gt(s(x),s(y)) -> gt(x,y)

The set of usable rules consists of

  r17, r18

Take the reduction pair:

  generalized weighted path order (>=MG, >G)
  
    base order 1:
  
      matrix interpretation with standard point-wise order:
      
        carrier: N^1
        order: standard order
        interpretations:
          app#_A(x1,x2) = x1 + x2
          cons_A(x1,x2) = x1 + x2 + 4
          gt_A(x1,x2) = x1 + x2 + 7
          s_A(x1) = x1 + 6
          zero_A() = 2
          true_A() = 1
          false_A() = 1
  
    base order 2:
  
      marked-algebra reduction triple (>=A, >=A!, >A!):
      
        max/plus interpretation on natural numbers:
        
          app#_A(x1,x2) = max{0, x1 - 20}
          cons_A(x1,x2) = max{x1 + 19, x2 + 19}
          gt_A(x1,x2) = max{16, x1 - 16, x2 - 14}
          s_A(x1) = x1 + 15
          zero_A = 0
          true_A = 14
          false_A = 14
          app#!_A(x1,x2) = max{1, x1 - 20, x2 - 1}
          cons!_A(x1,x2) = max{0, x1 - 11, x2 - 13}
          gt!_A(x1,x2) = max{4, x1 - 11, x2 - 16}
          s!_A(x1) = 3
          zero!_A = 3
          true!_A = 2
          false!_A = 0
  
    partial status:
  
      pi(app#) = [1, 2]
      pi(cons) = [1, 2]
      pi(gt) = []
      pi(s) = []
      pi(zero) = []
      pi(true) = []
      pi(false) = []

The following rules are removed:

  p1

Then no dependency pair remains.

-- Reduction pair.

Consider the dependency pair problem (P, R), where P consists of

p1: sum#(cons(x,cons(y,l))) -> sum#(cons(plus(x,y),l))

and R consists of:

r1: app(nil(),k) -> k
r2: app(l,nil()) -> l
r3: app(cons(x,l),k) -> cons(x,app(l,k))
r4: sum(cons(x,nil())) -> cons(x,nil())
r5: sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l))
r6: sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k)))))
r7: sum(plus(cons(|0|(),x),cons(y,l))) -> pred(sum(cons(s(x),cons(y,l))))
r8: pred(cons(s(x),nil())) -> cons(x,nil())
r9: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y)))))
r10: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x))
r11: plus(zero(),y) -> y
r12: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y))))
r13: id(x) -> x
r14: if(true(),x,y) -> x
r15: if(false(),x,y) -> y
r16: not(x) -> if(x,false(),true())
r17: gt(s(x),zero()) -> true()
r18: gt(zero(),y) -> false()
r19: gt(s(x),s(y)) -> gt(x,y)

The set of usable rules consists of

  r13, r15, r17, r18, r19

Take the reduction pair:

  generalized weighted path order (>=MG, >G)
  
    base order 1:
  
      matrix interpretation with standard point-wise order:
      
        carrier: N^1
        order: standard order
        interpretations:
          sum#_A(x1) = 3
          cons_A(x1,x2) = 3
          plus_A(x1,x2) = 5
          id_A(x1) = x1 + 11
          if_A(x1,x2,x3) = x3 + 3
          false_A() = 0
          gt_A(x1,x2) = x2 + 6
          s_A(x1) = x1 + 7
          zero_A() = 2
          true_A() = 1
  
    base order 2:
  
      marked-algebra reduction triple (>=A, >=A!, >A!):
      
        max/plus interpretation on natural numbers:
        
          sum#_A(x1) = max{0, x1 - 80}
          cons_A(x1,x2) = x2 + 24
          plus_A(x1,x2) = max{134, x1, x2}
          id_A(x1) = max{103, x1}
          if_A(x1,x2,x3) = max{136, x2, x3}
          false_A = 239
          gt_A(x1,x2) = max{239, x1 - 104, x2 - 344}
          s_A(x1) = max{103, x1}
          zero_A = 0
          true_A = 137
          sum#!_A(x1) = max{1, x1 - 34}
          cons!_A(x1,x2) = max{3, x2 - 2}
          plus!_A(x1,x2) = x1 + 23
          id!_A(x1) = x1 + 23
          if!_A(x1,x2,x3) = max{129, x3 - 138}
          false!_A = 0
          gt!_A(x1,x2) = max{127, x1 - 104, x2 - 104}
          s!_A(x1) = max{128, x1 - 7}
          zero!_A = 1
          true!_A = 0
  
    partial status:
  
      pi(sum#) = []
      pi(cons) = []
      pi(plus) = []
      pi(id) = [1]
      pi(if) = [3]
      pi(false) = []
      pi(gt) = [2]
      pi(s) = [1]
      pi(zero) = []
      pi(true) = []

The following rules are removed:

  p1

Then no dependency pair remains.

-- Reduction pair.

Consider the dependency pair problem (P, R), where P consists of

p1: plus#(s(x),s(y)) -> plus#(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y)))
p2: plus#(id(x),s(y)) -> plus#(x,if(gt(s(y),y),y,s(y)))
p3: plus#(s(x),x) -> plus#(if(gt(x,x),id(x),id(x)),s(x))

and R consists of:

r1: app(nil(),k) -> k
r2: app(l,nil()) -> l
r3: app(cons(x,l),k) -> cons(x,app(l,k))
r4: sum(cons(x,nil())) -> cons(x,nil())
r5: sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l))
r6: sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k)))))
r7: sum(plus(cons(|0|(),x),cons(y,l))) -> pred(sum(cons(s(x),cons(y,l))))
r8: pred(cons(s(x),nil())) -> cons(x,nil())
r9: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y)))))
r10: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x))
r11: plus(zero(),y) -> y
r12: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y))))
r13: id(x) -> x
r14: if(true(),x,y) -> x
r15: if(false(),x,y) -> y
r16: not(x) -> if(x,false(),true())
r17: gt(s(x),zero()) -> true()
r18: gt(zero(),y) -> false()
r19: gt(s(x),s(y)) -> gt(x,y)

The set of usable rules consists of

  r13, r14, r15, r16, r17, r18, r19

Take the reduction pair:

  generalized weighted path order (>=MG, >G)
  
    base order 1:
  
      matrix interpretation with standard point-wise order:
      
        carrier: N^1
        order: standard order
        interpretations:
          plus#_A(x1,x2) = 17
          s_A(x1) = 23
          if_A(x1,x2,x3) = x2 + x3 + 1
          gt_A(x1,x2) = 18
          not_A(x1) = x1 + 4
          id_A(x1) = x1 + 16
          true_A() = 1
          false_A() = 1
          zero_A() = 2
  
    base order 2:
  
      marked-algebra reduction triple (>=A, >=A!, >A!):
      
        max/plus interpretation on natural numbers:
        
          plus#_A(x1,x2) = max{0, x1 - 79, x2 - 84}
          s_A(x1) = x1 + 78
          if_A(x1,x2,x3) = max{76, x1 - 228, x2 + 1, x3}
          gt_A(x1,x2) = max{224, x1 - 157, x2 - 79}
          not_A(x1) = max{76, x1 - 140}
          id_A(x1) = max{6, x1 + 2}
          true_A = 1
          false_A = 2
          zero_A = 0
          plus#!_A(x1,x2) = max{x1 + 3, x2 + 2}
          s!_A(x1) = x1 + 145
          if!_A(x1,x2,x3) = max{147, x1 - 77, x2 - 3, x3 + 146}
          gt!_A(x1,x2) = max{144, x1 - 79, x2 - 79}
          not!_A(x1) = max{146, x1 - 225}
          id!_A(x1) = max{146, x1 - 444}
          true!_A = 12
          false!_A = 0
          zero!_A = 13
  
    partial status:
  
      pi(plus#) = []
      pi(s) = []
      pi(if) = [2, 3]
      pi(gt) = []
      pi(not) = [1]
      pi(id) = []
      pi(true) = []
      pi(false) = []
      pi(zero) = []

The following rules are removed:

  p1, p3



-- SCC decomposition.

Consider the dependency pair problem (P, R), where P consists of

p1: plus#(id(x),s(y)) -> plus#(x,if(gt(s(y),y),y,s(y)))

and R consists of:

r1: app(nil(),k) -> k
r2: app(l,nil()) -> l
r3: app(cons(x,l),k) -> cons(x,app(l,k))
r4: sum(cons(x,nil())) -> cons(x,nil())
r5: sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l))
r6: sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k)))))
r7: sum(plus(cons(|0|(),x),cons(y,l))) -> pred(sum(cons(s(x),cons(y,l))))
r8: pred(cons(s(x),nil())) -> cons(x,nil())
r9: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y)))))
r10: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x))
r11: plus(zero(),y) -> y
r12: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y))))
r13: id(x) -> x
r14: if(true(),x,y) -> x
r15: if(false(),x,y) -> y
r16: not(x) -> if(x,false(),true())
r17: gt(s(x),zero()) -> true()
r18: gt(zero(),y) -> false()
r19: gt(s(x),s(y)) -> gt(x,y)

The estimated dependency graph contains the following SCCs:

  {p1}


-- Reduction pair.

Consider the dependency pair problem (P, R), where P consists of

p1: plus#(id(x),s(y)) -> plus#(x,if(gt(s(y),y),y,s(y)))

and R consists of:

r1: app(nil(),k) -> k
r2: app(l,nil()) -> l
r3: app(cons(x,l),k) -> cons(x,app(l,k))
r4: sum(cons(x,nil())) -> cons(x,nil())
r5: sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l))
r6: sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k)))))
r7: sum(plus(cons(|0|(),x),cons(y,l))) -> pred(sum(cons(s(x),cons(y,l))))
r8: pred(cons(s(x),nil())) -> cons(x,nil())
r9: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y)))))
r10: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x))
r11: plus(zero(),y) -> y
r12: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y))))
r13: id(x) -> x
r14: if(true(),x,y) -> x
r15: if(false(),x,y) -> y
r16: not(x) -> if(x,false(),true())
r17: gt(s(x),zero()) -> true()
r18: gt(zero(),y) -> false()
r19: gt(s(x),s(y)) -> gt(x,y)

The set of usable rules consists of

  r14, r15, r17, r18, r19

Take the reduction pair:

  generalized weighted path order (>=MG, >G)
  
    base order 1:
  
      matrix interpretation with standard point-wise order:
      
        carrier: N^1
        order: standard order
        interpretations:
          plus#_A(x1,x2) = 1
          id_A(x1) = 22
          s_A(x1) = x1 + 16
          if_A(x1,x2,x3) = x2 + x3 + 12
          gt_A(x1,x2) = x2 + 15
          true_A() = 1
          false_A() = 1
          zero_A() = 2
  
    base order 2:
  
      marked-algebra reduction triple (>=A, >=A!, >A!):
      
        max/plus interpretation on natural numbers:
        
          plus#_A(x1,x2) = max{0, x1 - 345, x2 - 140}
          id_A(x1) = x1 + 8
          s_A(x1) = x1 + 100
          if_A(x1,x2,x3) = max{139, x1 - 1, x2 + 12, x3}
          gt_A(x1,x2) = max{21, x1 - 215, x2 - 101}
          true_A = 1
          false_A = 10
          zero_A = 0
          plus#!_A(x1,x2) = max{2, x1 - 5}
          id!_A(x1) = max{1, x1 - 241}
          s!_A(x1) = x1 + 252
          if!_A(x1,x2,x3) = max{253, x1 - 139, x2 - 11, x3 - 9}
          gt!_A(x1,x2) = max{16, x1 - 11, x2 - 101}
          true!_A = 8
          false!_A = 0
          zero!_A = 9
  
    partial status:
  
      pi(plus#) = []
      pi(id) = []
      pi(s) = [1]
      pi(if) = [3]
      pi(gt) = []
      pi(true) = []
      pi(false) = []
      pi(zero) = []

The following rules are removed:

  p1

Then no dependency pair remains.

-- Reduction pair.

Consider the dependency pair problem (P, R), where P consists of

p1: gt#(s(x),s(y)) -> gt#(x,y)

and R consists of:

r1: app(nil(),k) -> k
r2: app(l,nil()) -> l
r3: app(cons(x,l),k) -> cons(x,app(l,k))
r4: sum(cons(x,nil())) -> cons(x,nil())
r5: sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l))
r6: sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k)))))
r7: sum(plus(cons(|0|(),x),cons(y,l))) -> pred(sum(cons(s(x),cons(y,l))))
r8: pred(cons(s(x),nil())) -> cons(x,nil())
r9: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y)))))
r10: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x))
r11: plus(zero(),y) -> y
r12: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y))))
r13: id(x) -> x
r14: if(true(),x,y) -> x
r15: if(false(),x,y) -> y
r16: not(x) -> if(x,false(),true())
r17: gt(s(x),zero()) -> true()
r18: gt(zero(),y) -> false()
r19: gt(s(x),s(y)) -> gt(x,y)

The set of usable rules consists of

  (no rules)

Take the reduction pair:

  generalized weighted path order (>=MG, >G)
  
    base order 1:
  
      matrix interpretation with standard point-wise order:
      
        carrier: N^1
        order: standard order
        interpretations:
          gt#_A(x1,x2) = x1 + x2 + 5
          s_A(x1) = x1 + 4
  
    base order 2:
  
      marked-algebra reduction triple (>=A, >=A!, >A!):
      
        max/plus interpretation on natural numbers:
        
          gt#_A(x1,x2) = 0
          s_A(x1) = 42
          gt#!_A(x1,x2) = max{43, x1 - 43, x2 - 43}
          s!_A(x1) = x1 + 42
  
    partial status:
  
      pi(gt#) = [1]
      pi(s) = [1]

The following rules are removed:

  p1

Then no dependency pair remains.