YES

1 decompositions
 #0 -----------
   1: f(x) -> x
   2: f(x) -> f(f(x))

@Development Closedness
--- R
   1: f(x) -> x
   2: f(x) -> f(f(x))

--- S
   1: f(x) -> x
   2: f(x) -> f(f(x))