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 The names of specific people have been replaced by generic words (e.g., PersonX, PersonY, PersonZ).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 can be hindered by what is mentioned in the Tail or not. In this task, hindering introduces hindrances that obstruct the natural path to the achievement of a goal. For example, the event PersonX adopts a cat can be obstructed if PersonX is allergic to cats. 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.

Q: Head: PersonX stands in the gap<sep>Tail: People are prohibited from standing in the gap.

A: Yes
****
Q: Head: PersonX starts last night<sep>Tail: PersonX's dad will not let him play.

A: Yes
****
Q: Head: PersonX opens the envelope<sep>Tail: The envelope is already open.

A:
Yes
****