---- CR(R cup S)
---- [Klein and Hirokawa, 2012]
R:
F(x,y) -> c(y)
G(x) -> x
f(x) -> g(x)
g(x) -> c(x)
S:

CP_S(R):

CR(S):
see below.

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

CPS'(R):

CP(R):