YES

(VAR x y)
(RULES
  a(a(z(),x),a(z(),y)) -> a(x,a(a(z(),x),y))
  a(a(z(),x),z()) -> a(x,a(z(),z()))
  s(x) -> a(z(),x)
)

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

  a_A(x1,x2) = x2
  z_A = 1
  s_A(x1) = x1
  z#_A = 0
  s#_A(x1) = 0

and precedence:

s > a > z
)