YES

TRS:

  f(a(),f(f(a(),x),a())) -> f(f(a(),f(a(),x)),a())

max/plus interpretations on N:

  f_A(x1,x2) = max{5, 1, -1}
  f#_A(x1,x2) = max{0, -2 + x1, -4}
  a_A = 6
  a#_A = 1

precedence:

  f > a