MAYBE

Problem:
 double(0()) -> 0()
 double(s(x)) -> s(s(double(x)))
 +(x,0()) -> x
 +(x,s(y)) -> s(+(x,y))
 +(s(x),y) -> s(+(x,y))
 double(x) -> +(x,x)

Proof:
 DP Processor:
  DPs:
   double#(s(x)) -> double#(x)
   +#(x,s(y)) -> +#(x,y)
   +#(s(x),y) -> +#(x,y)
   double#(x) -> +#(x,x)
  TRS:
   double(0()) -> 0()
   double(s(x)) -> s(s(double(x)))
   +(x,0()) -> x
   +(x,s(y)) -> s(+(x,y))
   +(s(x),y) -> s(+(x,y))
   double(x) -> +(x,x)
  CDG Processor:
   DPs:
    double#(s(x)) -> double#(x)
    +#(x,s(y)) -> +#(x,y)
    +#(s(x),y) -> +#(x,y)
    double#(x) -> +#(x,x)
   TRS:
    double(0()) -> 0()
    double(s(x)) -> s(s(double(x)))
    +(x,0()) -> x
    +(x,s(y)) -> s(+(x,y))
    +(s(x),y) -> s(+(x,y))
    double(x) -> +(x,x)
   graph:
    +#(s(x),y) -> +#(x,y) -> +#(x,s(y)) -> +#(x,y)
    +#(s(x),y) -> +#(x,y) -> +#(s(x),y) -> +#(x,y)
    +#(x,s(y)) -> +#(x,y) -> +#(x,s(y)) -> +#(x,y)
    +#(x,s(y)) -> +#(x,y) -> +#(s(x),y) -> +#(x,y)
    double#(s(x)) -> double#(x) -> double#(s(x)) -> double#(x)
    double#(s(x)) -> double#(x) -> double#(x) -> +#(x,x)
    double#(x) -> +#(x,x) -> +#(x,s(y)) -> +#(x,y)
    double#(x) -> +#(x,x) -> +#(s(x),y) -> +#(x,y)
   SCC Processor:
    #sccs: 2
    #rules: 3
    #arcs: 8/16
    DPs:
     double#(s(x)) -> double#(x)
    TRS:
     double(0()) -> 0()
     double(s(x)) -> s(s(double(x)))
     +(x,0()) -> x
     +(x,s(y)) -> s(+(x,y))
     +(s(x),y) -> s(+(x,y))
     double(x) -> +(x,x)
    Open
    
    DPs:
     +#(s(x),y) -> +#(x,y)
     +#(x,s(y)) -> +#(x,y)
    TRS:
     double(0()) -> 0()
     double(s(x)) -> s(s(double(x)))
     +(x,0()) -> x
     +(x,s(y)) -> s(+(x,y))
     +(s(x),y) -> s(+(x,y))
     double(x) -> +(x,x)
    Open