YES
(ignored inputs)COMMENT from the collection of \cite{AT2012}
Rewrite Rules:
   [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)),
     +(?x,+(?y,?z)) -> +(+(?x,?y),?z),
     +(?x,?y) -> +(?y,?x) ]
Apply Direct Methods...
Inner CPs:
   [ +(+(+(?x_1,?y_1),?z_1),?z) = +(?x_1,+(+(?y_1,?z_1),?z)),
     +(+(?y_2,?x_2),?z) = +(?x_2,+(?y_2,?z)),
     +(?x_1,+(?x,+(?y,?z))) = +(+(?x_1,+(?x,?y)),?z),
     +(?x_1,+(?y_2,?x_2)) = +(+(?x_1,?x_2),?y_2),
     +(+(?x,+(?y,?z)),?z_1) = +(+(?x,?y),+(?z,?z_1)),
     +(?x_1,+(+(?x,?y),?z)) = +(+(?x_1,?x),+(?y,?z)) ]
Outer CPs:
   [ +(?x,+(?y,+(?y_1,?z_1))) = +(+(+(?x,?y),?y_1),?z_1),
     +(?x,+(?y,?z)) = +(?z,+(?x,?y)),
     +(+(?x_1,?y_1),?z_1) = +(+(?y_1,?z_1),?x_1) ]
not Overlay, check Termination...
unknown/not Terminating
unknown Knuth & Bendix
Linear
unknown Development Closed
Strongly Closed
Direct Methods: CR

Final result: CR
178.trs: Success(CR)
(1 msec.)