---- CR(R cup S)
---- [Klein and Hirokawa, 2012]
R:
f(g(g(x))) -> a()
f(g(h(x))) -> b()
f(h(g(x))) -> b()
f(h(h(x))) -> c()
g(x) -> h(x)
a() -> b()
b() -> c()
S:

CP_S(R):
f(h(g(___y408))) -> a()
f(g(h(___y407))) -> a()
f(h(h(___y410))) -> b()
f(h(h(___y411))) -> b()
CR(S):
see below.

---- CR(R)
---- [Hirokawa and Middeldorp, 2011]
R:

CPS'(R):

CP(R):