$ControlActiveSetting is a symbol whose value is True if it is evaluated while a control is active, or in certain other previewing situations.

When Mathematica transforms an expression such as x+x into 2x, it is treating the variable x in a purely symbolic or formal fashion. In such cases, x is a symbol which can ...

$SystemCharacterEncoding gives the default raw character encoding for the computer system on which Mathematica is being run.

 

Algebra`PolynomialContinuedFractions` was available as an add-on package in previous versions of Mathematica and is now available on the web at ...

Algebra`ReIm` was available as an add-on package in previous versions of Mathematica and is now available on the web at library.wolfram.com/infocenter/MathSource/6759.

Page Setup controls the size and shape of the pages to be printed.

Subsets[list] gives a list of all possible subsets of list. Subsets[list, n] gives all subsets containing at most n elements. Subsets[list, {n}] gives all subsets containing ...

 

The built-in function Reduce provides the functionality previously found in Algebra`InequalitySolve`.