MAYBE
(ignored inputs)COMMENT doi:10.4230/LIPIcs.FSCD.2016.33 [36] Example 24 submitted by: Takahito Aoto
Rewrite Rules:
   [ +(0,?y) -> ?y,
     +(s(0),?y) -> s(?y),
     +(+(?x,?y),?z) -> +(?x,+(?y,?z)),
     +(?x,?y) -> +(?y,?x),
     s(s(?x)) -> s(?x),
     s(?x) -> s(s(?x)) ]
Apply Direct Methods...
Inner CPs:
   [ +(s(s(0)),?y_1) = s(?y_1),
     +(?y,?z_2) = +(0,+(?y,?z_2)),
     +(s(?y_1),?z_2) = +(s(0),+(?y_1,?z_2)),
     +(+(?y_3,?x_3),?z_2) = +(?x_3,+(?y_3,?z_2)),
     s(s(s(?x_5))) = s(?x_5),
     +(+(?x,+(?y,?z)),?z_1) = +(+(?x,?y),+(?z,?z_1)),
     s(s(?x)) = s(s(?x)) ]
Outer CPs:
   [ ?y = +(?y,0),
     s(?y_1) = +(?y_1,s(0)),
     +(?x_2,+(?y_2,?z_2)) = +(?z_2,+(?x_2,?y_2)),
     s(?x_4) = s(s(s(?x_4))) ]
Linear
(inner) Parallel CPs: (not computed)
unknown Toyama (Parallel CPs)
Direct Methods: Can't judge

Combined result: Can't judge
574.trs: Failure(unknown CR)
(0 msec.)