Is it permissible to pray four rak'ahs after the Imam's three-rak'ah Witr, and should the intention be to pray four continuous rak'ahs in Tarawih?

If the Imam prays Witr with three rak'ahs, and the congregant wishes to add to his prayer, he can remain with the Imam to attain the virtue of qiyam al-layl (night prayer). He should then add a fourth rak'ah after the Imam's salutation to make the Imam's Witr an even number (shaf'). The intention for this prayer should be sunnah of qiyam al-layl. If the congregant wishes to pray Witr, he must intend it with a separate intention. Witr is a right upon every Muslim, and it can be performed with five, three, or one rak'ah. If the congregant prays Witr with his Imam, and then wishes to pray afterwards, he may pray as much as he desires without nullifying his initial Witr, because the Prophet (peace be upon him) prayed after Witr.