YES (VAR x0 x1 x y z) (RULES i(*(x0,x1)) -> *(i(x1),i(x0)) *(i(x0),*(x0,x1)) -> x1 *(i(x0),x0) -> 1() g(1(),x0) -> i(x0) i(1()) -> 1() i(i(x0)) -> x0 f(x0,x1) -> g(x0,*(i(x1),x0)) *(1(),x0) -> x0 *(x0,1()) -> x0 *(x1,*(i(x1),x0)) -> x0 *(x,i(x)) -> 1() *(*(x,y),z) -> *(x,*(y,z)) ) (COMMENT Termination is shown by ELPO with interpretations on natural numbers *_A(x1,x2) = x1 + x2 1_A = 0 i_A(x1) = x1 g_A(x1,x2) = x2 f_A(x1,x2) = x1 + x2 + 1 1#_A = 0 and precedence: f > g > i > * > 1 )