4. Notation used throughout

Throughout these notes, we rely on different formatting of text to provide semantic meaning. For instance a_variable has what is referred to as a literal style. Here’s a table showing the font and notation styles used throughout and what they mean.

Notation used

Sample	Meaning
a_variable	Refers to a variable with name a_variable in a program.
a_function()	Really just a different type of variable, but the parentheses indicate it’s a function.
python	This is a command and has the same style as the above 2, but refers to the python program (not the language). You figure out what is being referred to from the context.
$ command	Indicates a command executed at a terminal prompt.
<some variable>	You know the characters \(<\) and \(>\) from mathematical notation where they mean less than and greater than respectively. In this usage, we call them ‘angle brackets’ and they surround a variable that the user (you) needs to fill in.
\(a\)	Denotes a variable in the mathematical sense.