YES

Problem:
 active(__(__(X,Y),Z)) -> mark(__(X,__(Y,Z)))
 active(__(X,nil())) -> mark(X)
 active(__(nil(),X)) -> mark(X)
 active(U11(tt())) -> mark(U12(tt()))
 active(U12(tt())) -> mark(tt())
 active(isNePal(__(I,__(P,I)))) -> mark(U11(tt()))
 mark(__(X1,X2)) -> active(__(mark(X1),mark(X2)))
 mark(nil()) -> active(nil())
 mark(U11(X)) -> active(U11(mark(X)))
 mark(tt()) -> active(tt())
 mark(U12(X)) -> active(U12(mark(X)))
 mark(isNePal(X)) -> active(isNePal(mark(X)))
 __(mark(X1),X2) -> __(X1,X2)
 __(X1,mark(X2)) -> __(X1,X2)
 __(active(X1),X2) -> __(X1,X2)
 __(X1,active(X2)) -> __(X1,X2)
 U11(mark(X)) -> U11(X)
 U11(active(X)) -> U11(X)
 U12(mark(X)) -> U12(X)
 U12(active(X)) -> U12(X)
 isNePal(mark(X)) -> isNePal(X)
 isNePal(active(X)) -> isNePal(X)

Proof:
 Matrix Interpretation Processor: dim=1
  
  interpretation:
   [tt] = 0,
   
   [active](x0) = x0,
   
   [nil] = 0,
   
   [U11](x0) = x0 + 2,
   
   [__](x0, x1) = x0 + x1,
   
   [isNePal](x0) = 6x0 + 4,
   
   [U12](x0) = 2x0 + 2,
   
   [mark](x0) = x0
  orientation:
   active(__(__(X,Y),Z)) = X + Y + Z >= X + Y + Z = mark(__(X,__(Y,Z)))
   
   active(__(X,nil())) = X >= X = mark(X)
   
   active(__(nil(),X)) = X >= X = mark(X)
   
   active(U11(tt())) = 2 >= 2 = mark(U12(tt()))
   
   active(U12(tt())) = 2 >= 0 = mark(tt())
   
   active(isNePal(__(I,__(P,I)))) = 12I + 6P + 4 >= 2 = mark(U11(tt()))
   
   mark(__(X1,X2)) = X1 + X2 >= X1 + X2 = active(__(mark(X1),mark(X2)))
   
   mark(nil()) = 0 >= 0 = active(nil())
   
   mark(U11(X)) = X + 2 >= X + 2 = active(U11(mark(X)))
   
   mark(tt()) = 0 >= 0 = active(tt())
   
   mark(U12(X)) = 2X + 2 >= 2X + 2 = active(U12(mark(X)))
   
   mark(isNePal(X)) = 6X + 4 >= 6X + 4 = active(isNePal(mark(X)))
   
   __(mark(X1),X2) = X1 + X2 >= X1 + X2 = __(X1,X2)
   
   __(X1,mark(X2)) = X1 + X2 >= X1 + X2 = __(X1,X2)
   
   __(active(X1),X2) = X1 + X2 >= X1 + X2 = __(X1,X2)
   
   __(X1,active(X2)) = X1 + X2 >= X1 + X2 = __(X1,X2)
   
   U11(mark(X)) = X + 2 >= X + 2 = U11(X)
   
   U11(active(X)) = X + 2 >= X + 2 = U11(X)
   
   U12(mark(X)) = 2X + 2 >= 2X + 2 = U12(X)
   
   U12(active(X)) = 2X + 2 >= 2X + 2 = U12(X)
   
   isNePal(mark(X)) = 6X + 4 >= 6X + 4 = isNePal(X)
   
   isNePal(active(X)) = 6X + 4 >= 6X + 4 = isNePal(X)
  problem:
   active(__(__(X,Y),Z)) -> mark(__(X,__(Y,Z)))
   active(__(X,nil())) -> mark(X)
   active(__(nil(),X)) -> mark(X)
   active(U11(tt())) -> mark(U12(tt()))
   mark(__(X1,X2)) -> active(__(mark(X1),mark(X2)))
   mark(nil()) -> active(nil())
   mark(U11(X)) -> active(U11(mark(X)))
   mark(tt()) -> active(tt())
   mark(U12(X)) -> active(U12(mark(X)))
   mark(isNePal(X)) -> active(isNePal(mark(X)))
   __(mark(X1),X2) -> __(X1,X2)
   __(X1,mark(X2)) -> __(X1,X2)
   __(active(X1),X2) -> __(X1,X2)
   __(X1,active(X2)) -> __(X1,X2)
   U11(mark(X)) -> U11(X)
   U11(active(X)) -> U11(X)
   U12(mark(X)) -> U12(X)
   U12(active(X)) -> U12(X)
   isNePal(mark(X)) -> isNePal(X)
   isNePal(active(X)) -> isNePal(X)
  Matrix Interpretation Processor: dim=1
   
   interpretation:
    [tt] = 4,
    
    [active](x0) = x0,
    
    [nil] = 0,
    
    [U11](x0) = 4x0,
    
    [__](x0, x1) = x0 + x1,
    
    [isNePal](x0) = 4x0 + 1,
    
    [U12](x0) = x0 + 2,
    
    [mark](x0) = x0
   orientation:
    active(__(__(X,Y),Z)) = X + Y + Z >= X + Y + Z = mark(__(X,__(Y,Z)))
    
    active(__(X,nil())) = X >= X = mark(X)
    
    active(__(nil(),X)) = X >= X = mark(X)
    
    active(U11(tt())) = 16 >= 6 = mark(U12(tt()))
    
    mark(__(X1,X2)) = X1 + X2 >= X1 + X2 = active(__(mark(X1),mark(X2)))
    
    mark(nil()) = 0 >= 0 = active(nil())
    
    mark(U11(X)) = 4X >= 4X = active(U11(mark(X)))
    
    mark(tt()) = 4 >= 4 = active(tt())
    
    mark(U12(X)) = X + 2 >= X + 2 = active(U12(mark(X)))
    
    mark(isNePal(X)) = 4X + 1 >= 4X + 1 = active(isNePal(mark(X)))
    
    __(mark(X1),X2) = X1 + X2 >= X1 + X2 = __(X1,X2)
    
    __(X1,mark(X2)) = X1 + X2 >= X1 + X2 = __(X1,X2)
    
    __(active(X1),X2) = X1 + X2 >= X1 + X2 = __(X1,X2)
    
    __(X1,active(X2)) = X1 + X2 >= X1 + X2 = __(X1,X2)
    
    U11(mark(X)) = 4X >= 4X = U11(X)
    
    U11(active(X)) = 4X >= 4X = U11(X)
    
    U12(mark(X)) = X + 2 >= X + 2 = U12(X)
    
    U12(active(X)) = X + 2 >= X + 2 = U12(X)
    
    isNePal(mark(X)) = 4X + 1 >= 4X + 1 = isNePal(X)
    
    isNePal(active(X)) = 4X + 1 >= 4X + 1 = isNePal(X)
   problem:
    active(__(__(X,Y),Z)) -> mark(__(X,__(Y,Z)))
    active(__(X,nil())) -> mark(X)
    active(__(nil(),X)) -> mark(X)
    mark(__(X1,X2)) -> active(__(mark(X1),mark(X2)))
    mark(nil()) -> active(nil())
    mark(U11(X)) -> active(U11(mark(X)))
    mark(tt()) -> active(tt())
    mark(U12(X)) -> active(U12(mark(X)))
    mark(isNePal(X)) -> active(isNePal(mark(X)))
    __(mark(X1),X2) -> __(X1,X2)
    __(X1,mark(X2)) -> __(X1,X2)
    __(active(X1),X2) -> __(X1,X2)
    __(X1,active(X2)) -> __(X1,X2)
    U11(mark(X)) -> U11(X)
    U11(active(X)) -> U11(X)
    U12(mark(X)) -> U12(X)
    U12(active(X)) -> U12(X)
    isNePal(mark(X)) -> isNePal(X)
    isNePal(active(X)) -> isNePal(X)
   Matrix Interpretation Processor: dim=1
    
    interpretation:
     [tt] = 0,
     
     [active](x0) = x0,
     
     [nil] = 6,
     
     [U11](x0) = 2x0 + 2,
     
     [__](x0, x1) = x0 + x1,
     
     [isNePal](x0) = x0,
     
     [U12](x0) = 2x0,
     
     [mark](x0) = x0
    orientation:
     active(__(__(X,Y),Z)) = X + Y + Z >= X + Y + Z = mark(__(X,__(Y,Z)))
     
     active(__(X,nil())) = X + 6 >= X = mark(X)
     
     active(__(nil(),X)) = X + 6 >= X = mark(X)
     
     mark(__(X1,X2)) = X1 + X2 >= X1 + X2 = active(__(mark(X1),mark(X2)))
     
     mark(nil()) = 6 >= 6 = active(nil())
     
     mark(U11(X)) = 2X + 2 >= 2X + 2 = active(U11(mark(X)))
     
     mark(tt()) = 0 >= 0 = active(tt())
     
     mark(U12(X)) = 2X >= 2X = active(U12(mark(X)))
     
     mark(isNePal(X)) = X >= X = active(isNePal(mark(X)))
     
     __(mark(X1),X2) = X1 + X2 >= X1 + X2 = __(X1,X2)
     
     __(X1,mark(X2)) = X1 + X2 >= X1 + X2 = __(X1,X2)
     
     __(active(X1),X2) = X1 + X2 >= X1 + X2 = __(X1,X2)
     
     __(X1,active(X2)) = X1 + X2 >= X1 + X2 = __(X1,X2)
     
     U11(mark(X)) = 2X + 2 >= 2X + 2 = U11(X)
     
     U11(active(X)) = 2X + 2 >= 2X + 2 = U11(X)
     
     U12(mark(X)) = 2X >= 2X = U12(X)
     
     U12(active(X)) = 2X >= 2X = U12(X)
     
     isNePal(mark(X)) = X >= X = isNePal(X)
     
     isNePal(active(X)) = X >= X = isNePal(X)
    problem:
     active(__(__(X,Y),Z)) -> mark(__(X,__(Y,Z)))
     mark(__(X1,X2)) -> active(__(mark(X1),mark(X2)))
     mark(nil()) -> active(nil())
     mark(U11(X)) -> active(U11(mark(X)))
     mark(tt()) -> active(tt())
     mark(U12(X)) -> active(U12(mark(X)))
     mark(isNePal(X)) -> active(isNePal(mark(X)))
     __(mark(X1),X2) -> __(X1,X2)
     __(X1,mark(X2)) -> __(X1,X2)
     __(active(X1),X2) -> __(X1,X2)
     __(X1,active(X2)) -> __(X1,X2)
     U11(mark(X)) -> U11(X)
     U11(active(X)) -> U11(X)
     U12(mark(X)) -> U12(X)
     U12(active(X)) -> U12(X)
     isNePal(mark(X)) -> isNePal(X)
     isNePal(active(X)) -> isNePal(X)
    Matrix Interpretation Processor: dim=1
     
     interpretation:
      [tt] = 4,
      
      [active](x0) = x0,
      
      [nil] = 0,
      
      [U11](x0) = x0,
      
      [__](x0, x1) = 4x0 + x1 + 1,
      
      [isNePal](x0) = x0,
      
      [U12](x0) = 2x0,
      
      [mark](x0) = x0
     orientation:
      active(__(__(X,Y),Z)) = 16X + 4Y + Z + 5 >= 4X + 4Y + Z + 2 = mark(__(X,__(Y,Z)))
      
      mark(__(X1,X2)) = 4X1 + X2 + 1 >= 4X1 + X2 + 1 = active(__(mark(X1),mark(X2)))
      
      mark(nil()) = 0 >= 0 = active(nil())
      
      mark(U11(X)) = X >= X = active(U11(mark(X)))
      
      mark(tt()) = 4 >= 4 = active(tt())
      
      mark(U12(X)) = 2X >= 2X = active(U12(mark(X)))
      
      mark(isNePal(X)) = X >= X = active(isNePal(mark(X)))
      
      __(mark(X1),X2) = 4X1 + X2 + 1 >= 4X1 + X2 + 1 = __(X1,X2)
      
      __(X1,mark(X2)) = 4X1 + X2 + 1 >= 4X1 + X2 + 1 = __(X1,X2)
      
      __(active(X1),X2) = 4X1 + X2 + 1 >= 4X1 + X2 + 1 = __(X1,X2)
      
      __(X1,active(X2)) = 4X1 + X2 + 1 >= 4X1 + X2 + 1 = __(X1,X2)
      
      U11(mark(X)) = X >= X = U11(X)
      
      U11(active(X)) = X >= X = U11(X)
      
      U12(mark(X)) = 2X >= 2X = U12(X)
      
      U12(active(X)) = 2X >= 2X = U12(X)
      
      isNePal(mark(X)) = X >= X = isNePal(X)
      
      isNePal(active(X)) = X >= X = isNePal(X)
     problem:
      mark(__(X1,X2)) -> active(__(mark(X1),mark(X2)))
      mark(nil()) -> active(nil())
      mark(U11(X)) -> active(U11(mark(X)))
      mark(tt()) -> active(tt())
      mark(U12(X)) -> active(U12(mark(X)))
      mark(isNePal(X)) -> active(isNePal(mark(X)))
      __(mark(X1),X2) -> __(X1,X2)
      __(X1,mark(X2)) -> __(X1,X2)
      __(active(X1),X2) -> __(X1,X2)
      __(X1,active(X2)) -> __(X1,X2)
      U11(mark(X)) -> U11(X)
      U11(active(X)) -> U11(X)
      U12(mark(X)) -> U12(X)
      U12(active(X)) -> U12(X)
      isNePal(mark(X)) -> isNePal(X)
      isNePal(active(X)) -> isNePal(X)
     Matrix Interpretation Processor: dim=1
      
      interpretation:
       [tt] = 4,
       
       [active](x0) = x0 + 1,
       
       [nil] = 4,
       
       [U11](x0) = 3x0 + 2,
       
       [__](x0, x1) = 4x0 + x1 + 2,
       
       [isNePal](x0) = 4x0 + 1,
       
       [U12](x0) = 2x0 + 2,
       
       [mark](x0) = 3x0
      orientation:
       mark(__(X1,X2)) = 12X1 + 3X2 + 6 >= 12X1 + 3X2 + 3 = active(__(mark(X1),mark(X2)))
       
       mark(nil()) = 12 >= 5 = active(nil())
       
       mark(U11(X)) = 9X + 6 >= 9X + 3 = active(U11(mark(X)))
       
       mark(tt()) = 12 >= 5 = active(tt())
       
       mark(U12(X)) = 6X + 6 >= 6X + 3 = active(U12(mark(X)))
       
       mark(isNePal(X)) = 12X + 3 >= 12X + 2 = active(isNePal(mark(X)))
       
       __(mark(X1),X2) = 12X1 + X2 + 2 >= 4X1 + X2 + 2 = __(X1,X2)
       
       __(X1,mark(X2)) = 4X1 + 3X2 + 2 >= 4X1 + X2 + 2 = __(X1,X2)
       
       __(active(X1),X2) = 4X1 + X2 + 6 >= 4X1 + X2 + 2 = __(X1,X2)
       
       __(X1,active(X2)) = 4X1 + X2 + 3 >= 4X1 + X2 + 2 = __(X1,X2)
       
       U11(mark(X)) = 9X + 2 >= 3X + 2 = U11(X)
       
       U11(active(X)) = 3X + 5 >= 3X + 2 = U11(X)
       
       U12(mark(X)) = 6X + 2 >= 2X + 2 = U12(X)
       
       U12(active(X)) = 2X + 4 >= 2X + 2 = U12(X)
       
       isNePal(mark(X)) = 12X + 1 >= 4X + 1 = isNePal(X)
       
       isNePal(active(X)) = 4X + 5 >= 4X + 1 = isNePal(X)
      problem:
       __(mark(X1),X2) -> __(X1,X2)
       __(X1,mark(X2)) -> __(X1,X2)
       U11(mark(X)) -> U11(X)
       U12(mark(X)) -> U12(X)
       isNePal(mark(X)) -> isNePal(X)
      Matrix Interpretation Processor: dim=1
       
       interpretation:
        [U11](x0) = 2x0,
        
        [__](x0, x1) = x0 + 4x1 + 2,
        
        [isNePal](x0) = 3x0 + 4,
        
        [U12](x0) = 2x0 + 2,
        
        [mark](x0) = 4x0 + 1
       orientation:
        __(mark(X1),X2) = 4X1 + 4X2 + 3 >= X1 + 4X2 + 2 = __(X1,X2)
        
        __(X1,mark(X2)) = X1 + 16X2 + 6 >= X1 + 4X2 + 2 = __(X1,X2)
        
        U11(mark(X)) = 8X + 2 >= 2X = U11(X)
        
        U12(mark(X)) = 8X + 4 >= 2X + 2 = U12(X)
        
        isNePal(mark(X)) = 12X + 7 >= 3X + 4 = isNePal(X)
       problem:
        
       Qed