This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.1)


returns True if an element of list matches form, and False otherwise.
tests all parts of list specified by levelspec.
  • form can be a pattern.
  • The first argument of MemberQ can have any head, not necessarily List.
  • MemberQ immediately tests whether any expression in list matches form; Element asserts that x is an element of the symbolic domain dom.
  • MemberQ uses standard level specifications:
nlevels through n
Infinitylevels through Infinity
{n}level n only
{n1,n2}levels through
  • The default value for levelspec in MemberQ is .
  • A positive level n consists of all parts of expr specified by n indices.
  • A negative level -n consists of all parts of expr with depth n.
  • Level consists of numbers, symbols, and other objects that do not have subparts.
  • Level corresponds to the whole expression.
  • With the option setting Heads->True, MemberQ looks at heads of expressions and their parts.
Test whether is a member of a list:
Test whether is a member of a list:
Click for copyable input
MemberQ works with patterns:
Test down to level :
MemberQ normally only tests level :
Test whether is ever equal to 1 modulo 7:
MemberQ tests for structural matches, not numerical equality:
MemberQ does not test for subsequences:
FreeQ does:
MemberQ by default only operates at level :
Include level :
New in 1 | Last modified in 4