Different, but the Same

You'll find that most teachers will assign readings and problems in a similar way. There are differences, but most are so small as to not mention.

Commas will separate similar things while semi-colons will be used to separate not-so-similar things. For instance:

    Ch1;2.1,3

Here the reading assignment is all of chapter 1 as well as sections 1 and 3 of chapter 2. On the other hand:

    Ch1,2.1,3

Now the assignment is chapter 1, section 1 of chapter 2, and chapter 3. See the difference? Well, think it over a bit and maybe it'll click in place:

    Ch1;2.1,3          vs           Ch1,2.1,3