Block[{x, y, ...}, expr] specifies that expr is to be evaluated with local values for the symbols x, y, .... Block[{x = x_0, ...}, expr] defines initial local values for x, ...

Catch[expr] returns the argument of the first Throw generated in the evaluation of expr. Catch[expr, form] returns value from the first Throw[value, tag] for which form ...

f' represents the derivative of a function f of one argument. Derivative[n_1, n_2, ...][f] is the general form, representing a function obtained from f by differentiating n_1 ...

x/y or Divide[x, y] is equivalent to x y^-1.

Element[x, dom] or x \[Element] dom asserts that x is an element of the domain dom. Element[{x_1, x_2, ...}, dom] asserts that all the x_i are elements of dom. Element[patt, ...

Flat is an attribute that can be assigned to a symbol f to indicate that all expressions involving nested functions f should be flattened out. This property is accounted for ...

FromDigits[list] constructs an integer from the list of its decimal digits. FromDigits[list, b] takes the digits to be given in base b. FromDigits["string"] constructs an ...

If[condition, t, f] gives t if condition evaluates to True, and f if it evaluates to False. If[condition, t, f, u] gives u if condition evaluates to neither True nor False.

Implies[p, q] represents the logical implication p \[DoubleRightArrow] q.

Install["name"] starts a MathLink-compatible external program and installs Mathematica definitions to call functions in it.