InverseFourierTransform[expr, \[Omega], t] gives the symbolic inverse Fourier transform of expr. InverseFourierTransform[expr, {\[Omega]_1, \[Omega]_2, \ ...}, {t_1, t_2, ...
RadicalBoxOptions -> {opt_1 -> val_1, opt_2 -> val_2, ...} is an option for selections that specifies settings for RadicalBox objects.
FixedPoint[f, expr] starts with expr, then applies f repeatedly until the result no longer changes.
NHoldAll is an attribute which specifies that none of the arguments to a function should be affected by N.
ContextToFileName["context"] gives the string specifying the file name that is by convention associated with a particular context.
NumberPoint is an option for NumberForm and related functions which gives the string to use as a decimal point.
StackInhibit[expr] evaluates expr without modifying the evaluation stack.
$Aborted is a special symbol that is returned as the result from a calculation that has been aborted.
$LicenseID is a string that gives the license ID under which Mathematica is being run.
$Notebooks is True if Mathematica is being used with a notebook-based front end.