Mathematica provides a general mechanism for specifying constraints on patterns. All you need to do is to put /;condition at the end of a pattern to signify that it applies ...

patt /; test is a pattern which matches only if the evaluation of test yields True. lhs :> rhs /; test represents a rule which applies only if the evaluation of test yields ...

One of the unique strengths of Mathematica's core language is its powerful and succinct—yet highly readable—symbolic pattern language. Convenient both for immediate use in ...

At the core of Mathematica's symbolic programming paradigm is the concept of transformation rules for arbitrary symbolic patterns. Mathematica's pattern language conveniently ...

Mathematica's symbolic character allows a powerful unification of the notion of conditionals in programming and in mathematics.

Mathematica can represent not only data and programs, but also the execution history of programs, as symbolic expressions—which can be displayed, manipulated, and analyzed ...

AutoAction is an option for objects such as Slider, Locator, and Button that specifies whether they should automatically take action whenever the mouse pointer is over them, ...

Unicode: 000A. Raw operator. Inserted whenever a raw newline is entered on the keyboard. Forces a line break in an expression, fixing the indenting level at the time when the ...

NotebookDynamicExpression is an option for notebooks that specifies an expression to be dynamically updated whenever that notebook is open.

The replacement operator /. allows you to apply transformation rules to a specific expression. Often, however, you want to have transformation rules automatically applied ...