YES
(VAR x)
(RULES
a(u(x)) -> x
u(a(x)) -> x
v(c(v(x))) -> c(x)
v(c(c(x))) -> c(c(v(x)))
b(x) -> u(c(a(v(c(x)))))
c(a(a(x))) -> a(a(c(x)))
w(x) -> u(c(a(x)))
v(c(a(x))) -> u(u(c(c(a(v(c(x)))))))
c(a(c(x))) -> a(x)
v(u(x)) -> a(v(x))
v(a(x)) -> u(v(x))
c(u(x)) -> u(u(c(a(x))))
)