### Nested requests

OBJECTIVE: To understand and use the fundamental problem-solving element, Request-Response-Result, when requests are nested.
A response may make one or more requests. In this case the response becomes the current requesting equation. Responses to a requesting equation are indented one level to the right of the position of the requesting equation.

If there is more than one request, that is, sequential variables as described in Lesson 2, responses to each of the requests are made. When responses to all the requests have been completed, the previous requesting equation becomes the current requesting equation.

The following examples shows a simple case of nested requests in which each response makes one request.

The nesting can go to considerable depth. The following example illustrates this for a problem a bit more complex than the previous one.
The example also illustrates an important property of a problem statement. It can readily be seen that the problem statement is the source of information with which to respond to a request.

Problems of any consequence will have several nested request structures in the solution.

The problem statement is one of the sources of information needed to respond to requests.

A problem statement is not an object to be understood. It is only a source of information in the same sense as a dictionary or telephone book. It is a place to look for information to respond to what the equations ask for. Let the equation tell you what to look for. Equations talk.

## Request-Response-Result

Request-Response-Result is used repeatedly in our daily activities. Have you students journal use of this for a day. Have them identify situations in which sequential and nested requests were encountered and how responses generated from available information led to results.

Comments are important and appreciated. Please comment.
A SureMath solution. Copyright 1998, Howard C. McAllister.