TERMS SET AND CLEAR
The concept of the terms Set and Clear is important to understand. In program terms, to Set a bit means to force it high, i.e. to logic 1; the term Clear is used to mean that a bit is forced low, i.e. to logic 0.
Note, however, that in textual terms (i.e. in packages such as this) you are likely to come across the mixed use of the word set, in that you might be told to "set a bit low". In such cases, the implied meaning should be obvious from the context. In this example, low is the important word and force or make could have been used instead of set.
Now use the contents tree to navigate to Tutorial 2.5.