Function: math[retrieve] - selection from a list or set

Calling Sequence:

retrieve(l, yes, no)

Parameters:

l - a set or list
yes - a list or set with expressions
no - (optional) a list or set with expressions

Description:

The function returns those elements from a list or set l that include all the expressions in yes.

Optionally you may pass a list or set as the third argument to function retrieve with all those expressions that shall not be selected.

Expressions may be algebraic expressions, or names functions.

Examples:

> with(math):

> readlib(trigsubs):

> r := trigsubs(tan(x^2-1));

[Maple Math]
[Maple Math]
[Maple Math]

Retrieve those expression(s) that contain(s) the functions 'sin' and 'cos' and the expression [Maple Math] :

> retrieve(r, [sin, cos, x^2-1]);

[Maple Math]

Now retrieve those expressions from r that contain the tan function but not the cot function and also not the term [Maple Math] :

> retrieve(r, [tan], [cot, 1/2*x^2-1/2]);

[Maple Math]

See Also:

select , has .

Version History:

Version 1.0 as of January 01, 1998