YES
(VAR x)
(RULES
d(a(a(x))) -> a(d(a(x)))
d(a(c(x))) -> a(x)
b(a(x)) -> a(c(x))
c(d(a(x))) -> a(x)
c(a(x)) -> a(c(x))
b(d(x)) -> x
e(x) -> d(a(x))
)