TASK DEFINITION: In this task, you are given two phrases: Head and Tail, separated with <sep>. The Head and the Tail events are short phrases possibly involving participants. The names of specific people have been replaced by generic words (e.g., PersonX, PersonY, PersonZ). PersonX is always the subject of the event. You have to determine whether the Head happens after the Tail or not. Classify your answers into "Yes" and "No". The phrase may also contain "___", a placeholder that can be an object, a person, and/or an action.
PROBLEM: Head: PersonX acts in PersonY capacity<sep>Tail: to keep his army unit safe

SOLUTION: No

PROBLEM: Head: PersonX learns how to use it<sep>Tail: PersonX buys a camera

SOLUTION: Yes

PROBLEM: Head: PersonX accomplishes PersonX's objectives<sep>Tail: completes work

SOLUTION:
No