VerticalTilde[x, y, ...] displays as x\[VerticalTilde]y\[VerticalTilde]....

WindowSize is a notebook option that specifies the size of window that should be used to display a notebook on the screen.

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

$LicenseID is a string that gives the license ID under which Mathematica is being run.

$RootDirectory gives the root directory of your file system.

$Urgent gives the list of files and pipes to which urgent output from Mathematica is sent.

This loads packages containing some test problems and utility functions. One of the first and simplest methods for solving initial value problems was proposed by Euler: ...

Many differential equations exhibit some form of stiffness, which restricts the step size and hence effectiveness of explicit solution methods. A number of implicit methods ...

EdgeLabels is an option and property for Graph and related functions that specifies what labels and label positions should be used for edges.

EffectiveInterest[r, q] gives the effective interest rate corresponding to interest specification r, compounded at time intervals q.