YES

   1: g(a()) -> f(g(a()))
   2: g(b()) -> c()
   3: a() -> b()
   4: f(x1) -> h(x1,x1)
   5: h(x1,x2) -> c()

@Rule Labeling
--- R
   1: g(a()) -> f(g(a()))
   2: g(b()) -> c()
   3: a() -> b()
   4: f(x1) -> h(x1,x1)
   5: h(x1,x2) -> c()

--- S
   1: g(a()) -> f(g(a()))
   2: g(b()) -> c()
   3: a() -> b()
   4: f(x1) -> h(x1,x1)
   5: h(x1,x2) -> c()