The cow chases the dog. The cow chases the rabbit. The dog needs the cow. The dog needs the squirrel. The rabbit eats the squirrel. The rabbit is big. The rabbit needs the cow. The squirrel eats the cow. The squirrel is red. The squirrel needs the dog. If something needs the cow then it is green. If something chases the dog and the dog is green then the dog eats the rabbit. If something eats the rabbit then it eats the squirrel. If the squirrel chases the rabbit then the squirrel needs the cow. If something chases the rabbit then the rabbit chases the squirrel. If something chases the dog then the dog eats the cow.
The cow does not need the squirrel.