266  Index  Unsigned  constant  EBNF for, 165,218,229  syntax diagram for, 31, 231  integer  ERNF for, 150, 220, 229  syntax diagram for, 12,230  number  EBNF for, 150,219,229  syntax diagram for, 12, 231  real, EBNF for, 150, 220, 229  Until,  see  Repeat statement  Up-arrow,  see  Alternative symbols  Upper--case, letters, 10, 19,  148, 153  Value parameters, 107, 110, 113,  146  actual, 110, 187-188  formal, 110, 185  sample program using, III  specification, EBNF for, 185,  216,228  Var  parameters, 107, 11 0, 185-186  (see also  Variable parameters)  see  Variable declaration  Variable  accessing operations, 209  declaration, 7, 25,143,145,160  EBNF for, 161,215,229  part  EBNF for, 161,215,229  syntax diagram for, 25  and scope, 105, 178-179  example of, 162,219,229  EBNF for, identifier  EBNF for, 161,219,229  syntax diagram for, 231  parameters, 107, 110, 185-187  specification, EBNF for, 185,  216,229  sample program using, 111  read-only, 112  syntax diagram for, 30, 232  totally undefined, 161  undefined, 161  within activations, 179-180  Variables, 161-164  buffer, 87-89,163-164  component, 57, 65,161-163  entire, 161  global to procedure, 105  identified, 94-95, 163  kinds of, 28,161-164  local to procedure, 105  to represent data, 143  ~tandard,  128,211  Variant  EBNF for, 157,218,229  part  EBNF for, 157, 218, 229  of record, 70, 72,157,163  syntax diagram, 70  rl~cords,  69-73,144  and dynamic allocation, 99, 101,  191  examples of, 71-72,158  ~clector,  EBNF for, 157,218,229  syntax diagram, 70  While statements, 35,146,173-174  EBNFfor, 173,217,229  example of 36, 174  syntax diagram for, 35  , ,'hole number, 7  \~'ith  statements, 47, 73-75, 176-177  EBNF for, 176, 217, 229  syntax diagram for, 73  Word  symbols. 9,148,212  EBNF for, 148  (see  also  Reserved words)  \\ rite. 92, 135-139, 196,207,211  .tnd buffer variable evaluation, 87,  88,133,191  tnt! default file, 128, 194  'xamples, 138-139  .mllatted, 136-137,190,196-199  : lara meter  EBNF for. 196,219,229  li,t  EBNF for. 196,219,229  ,yntax diagram for, 136,234  \\'ltdn,92.135-139,198  oITid default file, 128  . IIlI  equivalent writes, 136, 198 