Similarly, example (6a) is a raising-to-object sentence; "Brian" raises to the object position of the verb "want." In contrast, (6b) is an object control sentence. The verb "persuade" has three theta-roles to assign: "agent" to "Jean", "theme" to "Brian", and "proposition" to the clause ["PRO to leave"]. There is no raising, but there is a PRO in the subject position of the embedded clause that takes the verb leave's only theta-role, "agent". Since Brian does not receive theta-role from "leave", it only bears one theta-role, nor does PRO receive a second theta-role from "persuade". Every argument only receives one theta-role, and every theta-role of the two predicates is assigned to only one argument. The sentence is thus grammatical.