YES

1 decompositions
 #1 -----------
   1: g(a(),x1) -> x1
   2: f(x2,a()) -> f(x2,g(x2,b()))
   3: g(h(x3),x4) -> g(x3,h(x4))

@Development Closedness
--- R
   1: g(a(),x1) -> x1
   2: f(x2,a()) -> f(x2,g(x2,b()))
   3: g(h(x3),x4) -> g(x3,h(x4))

--- S
   1: g(a(),x1) -> x1
   2: f(x2,a()) -> f(x2,g(x2,b()))
   3: g(h(x3),x4) -> g(x3,h(x4))