MAYBE

Problem:
 app(nil(),xs) -> nil()
 app(cons(x,xs),ys) -> cons(x,app(xs,ys))
 rev(nil()) -> nil()
 rev(cons(x,xs)) -> append(xs,rev(cons(x,nil())))

Proof:
 RT Transformation Processor:
  strict:
   app(nil(),xs) -> nil()
   app(cons(x,xs),ys) -> cons(x,app(xs,ys))
   rev(nil()) -> nil()
   rev(cons(x,xs)) -> append(xs,rev(cons(x,nil())))
  weak:
   
  Matrix Interpretation Processor:
   dimension: 1
   interpretation:
    [append](x0, x1) = x0 + x1,
    
    [rev](x0) = x0,
    
    [cons](x0, x1) = x0 + x1 + 9,
    
    [app](x0, x1) = x0 + x1 + 4,
    
    [nil] = 2
   orientation:
    app(nil(),xs) = xs + 6 >= 2 = nil()
    
    app(cons(x,xs),ys) = x + xs + ys + 13 >= x + xs + ys + 13 = cons(x,app(xs,ys))
    
    rev(nil()) = 2 >= 2 = nil()
    
    rev(cons(x,xs)) = x + xs + 9 >= x + xs + 11 = append(xs,rev(cons(x,nil())))
   problem:
    strict:
     app(cons(x,xs),ys) -> cons(x,app(xs,ys))
     rev(nil()) -> nil()
     rev(cons(x,xs)) -> append(xs,rev(cons(x,nil())))
    weak:
     app(nil(),xs) -> nil()
   Matrix Interpretation Processor:
    dimension: 1
    interpretation:
     [append](x0, x1) = x0 + x1 + 12,
     
     [rev](x0) = x0 + 2,
     
     [cons](x0, x1) = x0 + x1,
     
     [app](x0, x1) = x0 + x1 + 4,
     
     [nil] = 0
    orientation:
     app(cons(x,xs),ys) = x + xs + ys + 4 >= x + xs + ys + 4 = cons(x,app(xs,ys))
     
     rev(nil()) = 2 >= 0 = nil()
     
     rev(cons(x,xs)) = x + xs + 2 >= x + xs + 14 = append(xs,rev(cons(x,nil())))
     
     app(nil(),xs) = xs + 4 >= 0 = nil()
    problem:
     strict:
      app(cons(x,xs),ys) -> cons(x,app(xs,ys))
      rev(cons(x,xs)) -> append(xs,rev(cons(x,nil())))
     weak:
      rev(nil()) -> nil()
      app(nil(),xs) -> nil()
    Matrix Interpretation Processor:
     dimension: 2
     interpretation:
                         [1 0]     [1 0]  
      [append](x0, x1) = [0 0]x0 + [0 0]x1,
      
                  [1 0]     [12]
      [rev](x0) = [0 0]x0 + [9 ],
      
                       [1 0]          [4]
      [cons](x0, x1) = [0 0]x0 + x1 + [1],
      
                      [1 1]     [1 0]     [0]
      [app](x0, x1) = [0 1]x0 + [0 0]x1 + [3],
      
              [0]
      [nil] = [9]
     orientation:
                           [1 0]    [1 1]     [1 0]     [5]    [1 0]    [1 1]     [1 0]     [4]                     
      app(cons(x,xs),ys) = [0 0]x + [0 1]xs + [0 0]ys + [4] >= [0 0]x + [0 1]xs + [0 0]ys + [4] = cons(x,app(xs,ys))
      
                        [1 0]    [1 0]     [16]    [1 0]    [1 0]     [16]                                
      rev(cons(x,xs)) = [0 0]x + [0 0]xs + [9 ] >= [0 0]x + [0 0]xs + [0 ] = append(xs,rev(cons(x,nil())))
      
                   [12]    [0]        
      rev(nil()) = [9 ] >= [9] = nil()
      
                      [1 0]     [9 ]    [0]        
      app(nil(),xs) = [0 0]xs + [12] >= [9] = nil()
     problem:
      strict:
       rev(cons(x,xs)) -> append(xs,rev(cons(x,nil())))
      weak:
       app(cons(x,xs),ys) -> cons(x,app(xs,ys))
       rev(nil()) -> nil()
       app(nil(),xs) -> nil()
     Open