MAYBE

Problem:
 a(L(x)) -> L(a(x))
 R(a(a(x))) -> a(a(a(R(x))))
 b(L(x)) -> b(R(a(x)))
 R(b(x)) -> L(b(x))
 R(a(b(x))) -> L(a(b(x)))

Proof:
 Open