MAYBE
Input TRS:
      1: le(0(),y) -> true()
      2: le(s(x),0()) -> false()
      3: le(s(x),s(y)) -> le(x,y)
      4: minus(x,0()) -> x
      5: minus(0(),s(y)) -> 0()
      6: minus(s(x),s(y)) -> minus(x,y)
      7: plus(x,0()) -> x
      8: plus(x,s(y)) -> s(plus(x,y))
      9: mod(s(x),0()) -> 0()
      10: mod(x,s(y)) -> help(x,s(y),0())
      11: help(x,s(y),c) -> if(le(c,x),x,s(y),c)
      12: if(true(),x,s(y),c) -> help(x,s(y),plus(c,s(y)))
      13: if(false(),x,s(y),c) -> minus(x,minus(c,s(y)))
Number of strict rules: 13
Direct POLO(bPol) ... failed.
Uncurrying ... failed.
Dependency Pairs:
     #1: #minus(s(x),s(y)) -> #minus(x,y)
     #2: #if(false(),x,s(y),c) -> #minus(x,minus(c,s(y)))
     #3: #if(false(),x,s(y),c) -> #minus(c,s(y))
     #4: #help(x,s(y),c) -> #if(le(c,x),x,s(y),c)
     #5: #help(x,s(y),c) -> #le(c,x)
     #6: #if(true(),x,s(y),c) -> #help(x,s(y),plus(c,s(y)))
     #7: #if(true(),x,s(y),c) -> #plus(c,s(y))
     #8: #mod(x,s(y)) -> #help(x,s(y),0())
     #9: #le(s(x),s(y)) -> #le(x,y)
     #10: #plus(x,s(y)) -> #plus(x,y)
Number of SCCs: 4, DPs: 5
  SCC { #10 }
POLO(Sum)... succeeded.
      le	w: 0
      s 	w: x1 + 1
      #le	w: 0
      minus	w: 0
      #help	w: 0
      #plus	w: x2
      mod	w: 0
      false	w: 0
      true	w: 0
      0 	w: 0
      if	w: 0
      #minus	w: 0
      #mod	w: 0
      plus	w: 0
      #if	w: 0
      help	w: 0
    USABLE RULES: { }
    Removed DPs: #10
Number of SCCs: 3, DPs: 4
  SCC { #9 }
POLO(Sum)... succeeded.
      le	w: 0
      s 	w: x1 + 1
      #le	w: x2
      minus	w: 0
      #help	w: 0
      #plus	w: 0
      mod	w: 0
      false	w: 0
      true	w: 0
      0 	w: 0
      if	w: 0
      #minus	w: 0
      #mod	w: 0
      plus	w: 0
      #if	w: 0
      help	w: 0
    USABLE RULES: { }
    Removed DPs: #9
Number of SCCs: 2, DPs: 3
  SCC { #1 }
POLO(Sum)... succeeded.
      le	w: 0
      s 	w: x1 + 1
      #le	w: 0
      minus	w: 0
      #help	w: 0
      #plus	w: 0
      mod	w: 0
      false	w: 0
      true	w: 0
      0 	w: 0
      if	w: 0
      #minus	w: x2
      #mod	w: 0
      plus	w: 0
      #if	w: 0
      help	w: 0
    USABLE RULES: { }
    Removed DPs: #1
Number of SCCs: 1, DPs: 2
  SCC { #4 #6 }
POLO(Sum)... POLO(max)... QLPOS... POLO(mSum)... QWPOpS(mSum)... Mat2b... failed.
Finding a loop...  failed.