YES

(VAR x y z)
(RULES
  f(+(x,y)) -> +(f(x),f(y))
  +(+(x,y),z) -> +(x,+(y,z))
)

(COMMENT
Termination is shown by EKBO with interpretations on natural numbers

  +_A(x1,x2) = 1
  f_A(x1) = 2
  +#_A(x1,x2) = 0

weights

  w0 = 1
  w(+) = 0
  w(f) = 0

and precedence:

f > +
)