Prime numbers, sample  program for, 82-85  Procedural parameters, 107, 110,  117,147,185-188  sample program using, 120-121  ProceduralParameterSpecification,  EBNF for, 186,216,227  Procedures, 180, 181-182, 190-192  activation of, 33, 111, 170,  179-180  as actual parameters, 187-188  block,147  concept of, 102  declaration, 27, 102, 103, 178,  179,181  EBNF for, 182,215,227  examples of, 182  forward declaration of, 122,  125,181  heading, 105, 107, 181  EBNF for, 182,216,227  syntax diagram for, 103  identification, EBNF for, 182,  216,227  identifier, 105, 181  EBNF for, 182,219,227  predeclared, 190-193,204-207  syntax diagram for, 231  recursive 8, 113, 182  sample program using, 80, 96-97,  103-104,107-108,111,114- 115,116-117,118-119,120  statements, 33,106,146,170-171  EBNF for, 171,217,227  syntax diagram for, 206  ProcedureAndFunctionDeclarationPart  EBNF for, 181,215,227  syntax diagram for, 102  ProcedureOrFunctionHeading,  syntax diagram for, 102, 236  Processor, and ISO standard, 200  Productions, in EBNF, 3, 213  Program-point, 179  Program, 199-200  as EBNF start symbol, 214  block, 1, 146  development, 80-81, 106  EBNF for, 3, 199,215,227  heading, 1,3,21, 199-200  EBNF for, 3,199,215,227  syntax diagram, 4, 22  parameter list, EBNFfor, 199,215,  227  parameters, 199  syntax diagram for, 4, 21, 239  Programming  examples, 242-248  (see also  Language feature,  sample program using, e.g.,  Procedures, sample program using)  style, 8  Prompt interactive user,  sample program to, 133  Put, 88,128,190,206,211  Radix read, sample program for,  245-246  Random-access  of array, 57, 144  of record, 65, 144  of set, 76, 144  Read,206,211  and buffer variable evaluation,  87,88,132  and default file, 128  and packed variable, 190  procedure, 133-135, 191, 194-195  from text file, 92, 93  sample program using 92, 134  Readability, of program, 106  Readln, 206, 211  ,lIld buffer variable evaluation, 132  .lIld default file, 128  \)fpacked variable, 190  procedure, 133-134, 195-196  110111 text file, 92-93  Read-only variable,  hmmd identifier similar to, 112  Keal  number, 7  read, 134, 195  and subrange type, 53  type, 15, 19-20,143,153,210  262  Index 