The villagers Li and Chen are relatives and often exchange experiences in raising livestock and poultry. Li has a hobby, as long as he raises fish, he must raise ducks; Chen also has a hobby. If he does not raise pigs, he definitely does not raise ducks. Can it be launched accordingly? ['If the villager Chen raises pigs or fish, then definitely raise ducks or fish.', 'If the villager Chen raises both ducks and fish, then he must raise both pigs and fish.', 'If the villager Li does not raise fish, he will not raise ducks.', 'If the villager Lee raises both fish and ducks, he will raise pigs.']