YES

---- CR(R)
---- R : linear and strongly closed [Huet, 1980]
R:
b(a(b(b(x)))) -> b(b(b(a(b(x)))))
b(a(a(b(b(x))))) -> b(a(b(b(a(a(b(x)))))))
b(a(a(a(b(b(x)))))) -> b(a(a(b(b(a(a(a(b(x)))))))))
CP(R):
b(a(b(b(b(b(a(b(___y1)))))))) -> b(b(b(a(b(a(b(b(___y1))))))))
b(a(a(b(b(b(b(a(b(___y3))))))))) -> b(a(b(b(a(a(b(a(b(b(___y3))))))))))
b(a(a(a(b(b(b(b(a(b(___y5)))))))))) ->
  b(a(a(b(b(a(a(a(b(a(b(b(___y5))))))))))))
b(a(b(b(a(b(b(a(a(b(___y7)))))))))) -> b(b(b(a(b(a(a(b(b(___y7)))))))))
b(a(a(b(b(a(b(b(a(a(b(___y9))))))))))) ->
  b(a(b(b(a(a(b(a(a(b(b(___y9)))))))))))
b(a(a(a(b(b(a(b(b(a(a(b(___y11)))))))))))) ->
  b(a(a(b(b(a(a(a(b(a(a(b(b(___y11)))))))))))))
b(a(b(b(a(a(b(b(a(a(a(b(___y13)))))))))))) ->
  b(b(b(a(b(a(a(a(b(b(___y13))))))))))
b(a(a(b(b(a(a(b(b(a(a(a(b(___y15))))))))))))) ->
  b(a(b(b(a(a(b(a(a(a(b(b(___y15))))))))))))
b(a(a(a(b(b(a(a(b(b(a(a(a(b(___y17)))))))))))))) ->
  b(a(a(b(b(a(a(a(b(a(a(a(b(b(___y17))))))))))))))