YES

TRS:

  a__first(0(),X) -> nil()
  a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z))
  a__from(X) -> cons(mark(X),from(s(X)))
  mark(first(X1,X2)) -> a__first(mark(X1),mark(X2))
  mark(from(X)) -> a__from(mark(X))
  mark(0()) -> 0()
  mark(nil()) -> nil()
  mark(s(X)) -> s(mark(X))
  mark(cons(X1,X2)) -> cons(mark(X1),X2)
  a__first(X1,X2) -> first(X1,X2)
  a__from(X) -> from(X)

linear polynomial interpretations on N:

  a__first_A(x1,x2) = x1 + x2 + 3
  a__first#_A(x1,x2) = x1 + x2 + 3
  0_A = 1
  0#_A = 1
  nil_A = 1
  nil#_A = 0
  s_A(x1) = x1
  s#_A(x1) = x1
  cons_A(x1,x2) = x1 + 1
  cons#_A(x1,x2) = x1
  mark_A(x1) = x1
  mark#_A(x1) = x1 + 1
  first_A(x1,x2) = x1 + x2 + 3
  first#_A(x1,x2) = 2
  a__from_A(x1) = x1 + 2
  a__from#_A(x1) = x1 + 2
  from_A(x1) = x1 + 2
  from#_A(x1) = 0

precedence:

  a__first > first = a__from > cons = mark > 0 = s = from > nil