The cow needs the dog. The dog needs the cow. If something eats the cow then the cow is green. If something eats the dog and it does not need the dog then the dog is not green. If something needs the cow then the cow eats the dog. If something eats the dog and it is not kind then it sees the cow. If something sees the cow and it does not need the dog then it is not green. If the cow does not eat the dog then the dog needs the cow.
The cow does not need the dog.