# Defining Functions That Use Lists - HP 50g User Manual

Graphing calculator.

In both cases, you can either type out the MAP command (as in the examples
above) or select the command from the CAT menu.
The following call to function MAP uses a program instead of a function as
second argument:

## Defining functions that use lists

In Chapter 3 we introduced the use of the DEFINE function ( „à) to
create functions of real numbers with one or more arguments. A function
defined with DEF can also be used with list arguments, except that, any function
incorporating an addition must use the ADD operator rather than the plus sign
(+). For example, if we define the function F(X,Y) = (X-5)*(Y-2), shown here
in ALG mode:
we can use lists (e.g., variables L1 and L2, defined earlier in this Chapter) to
evaluate the function, resulting in:
Since the function statement includes no additions, the application of the
function to list arguments is straightforward. However, if we define the function
G(X,Y) = (X+3)*Y, an attempt to evaluate this function with list arguments (L1,
L2) will fail:
To fix this problem we can edit the contents of variable @@@G@@@ , which we can list
in the stack by using ...@@@G@@@,
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