$Aborted (Built-in Mathematica Symbol)

$Aborted is a special symbol that is returned as the result from a calculation that has been aborted.

$AssertFunction (Built-in Mathematica Symbol)

$AssertFunction specifies a function to apply to assertions that fail.

$Assumptions (Built-in Mathematica Symbol)

$Assumptions is the default setting for the Assumptions option used in such functions as Simplify, Refine, and Integrate.

$BaseDirectory (Built-in Mathematica Symbol)

$BaseDirectory gives the base directory in which systemwide files to be loaded by Mathematica are conventionally placed.

$BatchInput (Built-in Mathematica Symbol)

$BatchInput is True if input in the current session is being fed directly to the Mathematica kernel in batch mode.

$BatchOutput (Built-in Mathematica Symbol)

$BatchOutput is True if output in the current session is being sent in batch mode, suitable for reading by other programs.

$ByteOrdering (Built-in Mathematica Symbol)

$ByteOrdering gives the native ordering of bytes in binary data on your computer system.

$Canceled (Built-in Mathematica Symbol)

$Canceled is a symbol returned when notebook input is canceled, for example from a dialog box.

$CharacterEncoding (Built-in Mathematica Symbol)

$CharacterEncoding specifies the default raw character encoding to use for input and output functions.

$CharacterEncodings (Built-in Mathematica Symbol)

$CharacterEncodings gives the list of character encodings that can be used.