StringQ[expr] gives True if expr is a string, and False otherwise.

x - y is equivalent to x + (-1*y).

Symbol["name"] refers to a symbol with the specified name.

SyntaxInformation[f] gives information used to generate syntax coloring and other advisories when f[...] is entered as input.

TimeConstraint is an option for various algorithmic functions which specifies how long to spend trying a particular transformation or part of an algorithm.

TraceOriginal is an option for Trace and related functions which specifies whether to test the form of each expression before its head and arguments are evaluated.

Translate[g, {x, y, ...}] represents graphics primitives g translated by the vector {x, y, ...}. Translate[g, {{x_1, y_1, ...}, {x_2, y_2, ...}, ...}] represents multiple ...

Transparent represents perfect transparency in graphics or style specifications.

VertexDegree[g] gives the list of vertex degrees for all vertices in the graph g.VertexDegree[g, v] gives the vertex degree for the vertex v.

WindowMargins is a notebook option that specifies what margins to leave around the window that is used to display the notebook on the screen.