Element

Element[x, dom] or asserts that x is an element of the domain dom.

Element[, , ... , dom] asserts that all the are elements of dom.

Element[patt, dom] asserts that any expression matching the pattern patt is an element of dom.

can be entered as x elem dom or x \[Element] dom.

Element can be used to set up assumptions in Simplify and related functions.

Possible domains are:

if possible evaluates immediately when x is numeric.

Examples: Pi Algebraics ; Pi Reals .

( | | ... ) dom is equivalent to , , ... dom.

, , ... dom evaluates to ( | | ... ) dom if its truth or falsity cannot immediately be determined.

See The Mathematica Book: Section 1.4.6 and Section 3.3.10.

See also: Simplify, MemberQ, IntegerQ, Assumptions, Condition, PatternTest, Equal, Less, NotElement.

Further Examples