Count
(Built-in Mathematica Symbol) Count[list, pattern] gives the number of elements in list that match pattern. Count[expr, pattern, levelspec] gives the total number of subexpressions matching pattern that ...
ExclusionsStyle is an option to plotting functions that specifies how to render subregions excluded according to Exclusions.
expr /. rules applies a rule or list of rules in an attempt to transform each subpart of an expression expr.
Rule
(Built-in Mathematica Symbol) lhs -> rhs or lhs -> rhs represents a rule that transforms lhs to rhs.
TextRecognize[image] recognizes text in image and returns it as a string.
TimeConstrained[expr, t] evaluates expr, stopping after t seconds. TimeConstrained[expr, t, failexpr] returns failexpr if the time constraint is not met.
Timing
(Built-in Mathematica Symbol) Timing[expr] evaluates expr, and returns a list of the time in seconds used, together with the result obtained.
$ScheduledTask returns the current ScheduledTaskObject.
Functions for manipulating elements in explicit lists. This gives a list with x prepended. This inserts x so that it becomes element number 2.
Representations of real intervals. This represents all numbers between -2 and +5. The square of any number between -2 and +5 is always between 0 and 25.