O grants to A and his heirs, but if the land is used for other than agricultural purposes, then O may re-enter and resume her prior estate. The state of the title: A has a fee simple subject to a condition subsequent, and it is a possessory interest. O has a right of entry, also known as a power of termination, and it is, of course, in a fee simple absolute. For those of you reviewing, all interests are legal, not equitable.