The symbolic language paradigm of the Wolfram Language takes the concept of variables and functions to a new level. In the Wolfram Language a variable can not only stand for a value, but can also be used purely symbolically. And building on the Wolfram Language's powerful pattern language, "functions" can be defined not just to take arguments, but to transform a pattern with any structure.

x=… — set a variable

f[x_]:=… — define a function that takes any single argument

Assignments »

Set (= ) — immediate assignment (right-hand side evaluated immediately)

SetDelayed (:= ) — delayed assignment (right-hand side evaluated only when used)

Unset (=. ) — unset a variable

Clear — clear a function definition

Function Argument Patterns »

__ (BlankSequence )  ▪ p|p (Alternatives )  ▪ p:e (Optional )

Bodies of Functions »

Module , ... — scope local variables

e;e;e (CompoundExpression ) — execute expressions in sequence

Function Attributes »

Attributes   ▪ Flat   ▪ Orderless   ▪ Listable   ▪ HoldFirst   ▪ Protected