YES

1 decompositions
 #0 -----------
   1: f(i(x),g(a())) -> f(j(x,x),g(b()))
   2: b() -> a()
   3: i(x) -> j(x,x)

@Parallel Closedness
--- R
   1: f(i(x),g(a())) -> f(j(x,x),g(b()))
   2: b() -> a()
   3: i(x) -> j(x,x)

--- S
   1: f(i(x),g(a())) -> f(j(x,x),g(b()))
   2: b() -> a()
   3: i(x) -> j(x,x)