TraceDepth is an option for Trace and related functions which specifies the maximum nesting of evaluation chains that are to be included.
TrueQ
(Built-in Mathematica Symbol) TrueQ[expr] yields True if expr is True, and yields False otherwise.
WriteString[channel, expr_1, expr_2, ...] converts the expr_i to strings, and then writes them in sequence to the specified output channel.
$Context is a global variable that gives the current context.
$InputFileName is a global variable whose value is the absolute file name of the input file from which input to Mathematica is currently being sought.
$Input
(Built-in Mathematica Symbol) $Input is a global variable whose value is the name of the stream from which input to Mathematica is currently being sought.
$MachineName is a string that gives the assigned name of the computer on which Mathematica is being run, if such a name is defined.
$Packages gives a list of the contexts corresponding to all packages which have been loaded in your current Mathematica session.
$SessionID is a number set up to be unique to a particular Mathematica session.
Mathematica 8 provides functions that allow developers to implement file format converters to be integrated with the Mathematica Import and Export framework. You can ...