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## H.A. Procedures 

Throughout the example programs in this User Manual, the predeclared procedures Read, Readln, Write, and Writeln are used. This section describes how to build your own "programmer-declared" procedures; in fact, Programs 8.2 and 1 0.1 use them. 

The procedure declaration serves to define a program part and to associate it with an identifier, so that it can be activated by a procedure statement. The declaration has the same form as a program, except it is introduced by a procedure heading instead of a program heading. 

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Recall Program 6.1 that found the minimum and maximum values in a list of integers. As an extension, say that n increments are added to A [ 1] ... A [ n] , then Mi n and Max are again computed. The resulting program, which employs a procedure to determine Min and Max, follows. 

program MinMax2(Input,Output); { Program 11.1 - Extend Program 6.1 by introducing a procedure. } const MaxSize = 20; type ListSize = 1 .. MaxSize; var Increment: Integer; Item: ListSize; A: array [ListSize] of Integer; procedure MinMax; var Item: ListSize; Min, Max, First, Second: Integer; 

