The function member determines if x is a member of the set, list, Array, Matrix, Vector, table, function, or module s.  It returns true if so, and false otherwise.

If s is a table, member tests whether x is a value in the table.

If a third argument 'p' is present and member yields true, the position of the first x in s is assigned to p in the case of sets, lists, and functions, while the member instance is assigned to the name p if s is a module. Position is determined as the index in the case of an rtable or module, and ith operand in the case of other data-structures.

The member command is thread safe as of Maple 15, provided that the name p, if used, is not shared between threads.

For more information on thread safety, see index/threadsafe.

$\mathrm{member}\left(y\,\left\{x\,y\,z\right\}\right)$

$\mathrm{true}$

$\mathrm{member}\left(y\,\left\{xy\,yz\right\}\right)$

$\mathrm{false}$

$\mathrm{member}\left(xy\,\left[xy\,w+u\,y\right]\right)$

$\mathrm{true}$

$\mathrm{member}\left(y\,⟨x\,y\,z⟩\right)$

$\mathrm{true}$

$\mathrm{member}\left(y\,\mathrm{table}\left(\left[x\,y\,z\right]\right)\right)$

$\mathrm{true}$

$\mathrm{member}\left(w\,\left[x\,y\,w\,u\right]\,'k'\right)$

$\mathrm{true}$

$k$

$3$

$\mathrm{member}\left(v\,f\left(u\,v\,w\right)\,'k'\right)$

$\mathrm{true}$

$k$

$2$

$m≔\mathbf{module}\left(\right)\mathrm{\_export}\left(e\right)\mathbf{end\; module}\:$

$\mathrm{member}\left(e\,m\right)$

$\mathrm{true}$

$\mathrm{member}\left(e\,m\,'p'\right)\:$

$p$

$e$

$\mathrm{member}\left(f\,m\right)$

$\mathrm{false}$

The member command was updated in Maple 2023.

The s parameter was updated in Maple 2023.