264  Index  Set  (continued)  data types, in type taxonomy, 55,  210  declaration, example of, 78  difference, 78, 145, 168,209  equality, 78  implementation of, 83  inclusion, 78, 208  inequality, 78  intersection, 78, 145, 168,209  membership, 76, 78,  208  operators, 78-80, 146, 168-169  sample program using, 79-80,  82-85, 129-131  types  definition of, 76, 158  EBNF for, 158,218,228  syntax diagram for, 76  union, 78, 146, 169,209  Side effects, 125-126, 146  Sign  EBNF for, 150, 220, 228  (see also  Arithmetic operators)  SignedInteger, EBNF for, 150  SignedNumber, EBNF for, 150  SignedReal, EBNF for, 150  Simple  data types, in type taxonomy, 14,  15,210  expressions, 31, 165-167  EBNF for, 165, 217, 228  syntax diagrams for, 31, 233  statements, 170-172  EBNF for, 170,216,228  types, 14-20, 143, 153-154  EBNFfor, 153,217,228  and function result, 122, 146  predefined, 15, 154-155  syntax diagram for, 15  (see also  Ordinal types, Real)  Sin, 20, 193, 206, 211  Sine,  see  Sin  SkipBlanks, sample procedure for,  134-135  Space, as separator, 150  (see also  Blank)  SpecialSymbol, EBNF for, 149  Spelling  of directive, 149  of identifier, 149  of label, 178  and scope, 178  of word symbol, 149  Sqr, 18, 20, 36, 192, 206, 211  Sqrt, 20,193,207,211  Square root, example function for,  183  (see also  Sqrt)  Square,  see  Sqr  Standard Pascal, 147,200-201,203  Start symbol, for EBNF for Pascal,  214  Statement, 1, 170-177  compound,22,172  EBNF for, 170, 216, 228  empty, 34, 44, 170  part  EBNF for, 170,215,228  syntax diagram for, 22  'ieparators, 7, 34  sequence, EBNF for, 172,216,228  ,imple or structured, 28  syntax diagram for, 29, 238  Static variables, 94, 145  Stepwise refinement, for  programming, 81, 242-245  String  constants, 12-13, 150-151  construction, 209  element, EBNF for, 151,220,228  parameters, 117  types, 63, 155, 156  and compatibility, 159  ""rite, 135, 137, 198-199  (see also  Character strings)  'itrllctllred  programming, 81  ,taternents, 146, 172-177  EBNFfor, 172,217,228  t) pe identifier, EBNF for, 155,  219,228  t)pes, 14, 1..J-4, 155-159  EBNFfor, 155,217,228  syntax diagram for, 56  taxonomy of, 55, 210 