RowBox[{box_1, box_2, ...}] is a low-level box construct that represents a row of boxes or strings in a notebook expression.

SpheroidalJoiningFactor[n, m, \[Gamma]] gives the spheroidal joining factor with degree n and order m.

SpheroidalS2Prime[n, m, \[Gamma], z] gives the derivative with respect to z of the radial spheroidal function S_n^m, (2)(\[Gamma], z) of the second kind.

SubscriptBox[x, y] is the low-level box representation for x_y in notebook expressions.

SuperscriptBox[x, y] is the low-level box representation for x^y in notebook expressions.

Trig is an option for various polynomial manipulation functions that specifies whether trigonometric functions should be treated like polynomial elements.

UnderoverscriptBox[x, y, z] is the low-level box representation for x_y^z in notebook expressions.

When you create or use Mathematica packages, you will often want to refer to files in a system-independent way. You can use contexts to do this. The basic idea is that on ...

DiscreteLyapunovSolve[a, c] finds the numeric solution x of the discrete matrix equation a.x.a\[ConjugateTranspose] - x == c.DiscreteLyapunovSolve[a, b, c] solves a.x.b - x ...

Distribute[f[x_1, x_2, ...]] distributes f over Plus appearing in any of the x_i. Distribute[expr, g] distributes over g. Distribute[expr, g, f] performs the distribution ...