YES

TRS:

  a__f(f(a())) -> a__f(g(f(a())))
  mark(f(X)) -> a__f(mark(X))
  mark(a()) -> a()
  mark(g(X)) -> g(X)
  a__f(X) -> f(X)

linear polynomial interpretations on N:

  a__f_A(x1) = 2
  a__f#_A(x1) = x1 + 2
  f_A(x1) = 2
  f#_A(x1) = 1
  a_A = 1
  a#_A = 0
  g_A(x1) = 1
  g#_A(x1) = 0
  mark_A(x1) = 2
  mark#_A(x1) = 5

precedence:

  a__f > f = g > mark > a