Sorry, I usually put in a key, forgot this time, and the notes on Dream World section and hidden ability is simply inexperience. Also thanks for the tip about punctuation. However, both my corrections of semicolons were correct. After consulting the official use of semicolon from a reputable site on the Internet I confirmed what I thought. A semicolon separates two clauses that could both stand on their own when connection between the two is wanted that cannot be achieved with a full stop. In both my alterations, the second clause could not stand on its own. In the first instance, the second clause was a list, which is preceded by a colon. In my second correction, "the set that ...., the set that ...." cannot stand on its own, so requires a comma.
Check of you do not believe me but I stand by those alterations