TrigFactorList[expr] factors trigonometric functions in expr, yielding a list of lists containing trigonometric monomials and exponents.
WordCharacter represents a letter or digit character in StringExpression.
WriteString[channel, expr_1, expr_2, ...] converts the expr_i to strings, and then writes them in sequence to the specified output channel.
ZeroWidthTimes is an option for selections that specifies whether blank spaces representing multiplication are explicitly shown.
$ControlActiveSetting is a symbol whose value is True if it is evaluated while a control is active, or in certain other previewing situations.
$DisplayFunction gives the default setting for the option DisplayFunction in graphics functions.
$Inspector is a global variable which gives a function to apply when the inspector is invoked from an interrupt menu.
$VersionNumber is a real number which gives the current Mathematica kernel version number, and increases in successive versions.
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 ...
Mathematical Notation in Notebooks Special Characters Names of Symbols and Mathematical Objects