Mathematica provides systemwide support for a large number of special characters. Each character has a name and a number of shortcut aliases. They are fully supported by the ...

In many cases, you will find it convenient to communicate with external programs at a high level, and to exchange structured data with them. On almost all computer systems, ...

The Part function allows you to access specific parts of Mathematica expressions. But particularly when your expressions have fairly uniform structure, it is often convenient ...

Defining local constants. Module allows you to set up local variables, to which you can assign values and then change them. Often, however, all you really need are local ...

Low-level functions for converting between expressions and boxes. MakeBoxes generates boxes without evaluating its input. MakeExpression interprets boxes but uses ...

"Defining Functions" discusses how you can define functions in Mathematica. In a typical case, you would type in f[x_]=x^2 to define a function f. (Actually, the definitions ...

The replacement operator /. allows you to apply transformation rules to a specific expression. Often, however, you want to have transformation rules automatically applied ...

When you have numerical data, it is often convenient to find a simple formula that approximates it. For example, you can try to "fit" a line or curve through the points in ...

Converting between symbols and their names. Here is the symbol x. Its name is a string.

If you use a text-based interface to Mathematica, then the input you give must consist only of characters that you can type directly on your computer keyboard. But if you use ...