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Show 15 b. Literale 1. ß Semantics. Mean« undefined. It is the rMtt&t SI illegal operations. All identifiers are set to this at declaration time. Pragmatics. The logical word is flagged. Justification. Allows a much more free syntax while still permitting a check of illegality. 2. oo Semantics. Is the result of division by zero. It is also used to map extendable arrays. Pragmatics. The logical word is flagged. Justification. Permits checking for overflow and declaring unspecifxed bounds without giving rise to a fatal error. 3. <number> Semantics. A fraction of unspecified precxsion. PriagHtatics. Space is created to confeai« it, Justification. Useful for arithmetic. 4. Vtext:^' Semantics. A text literal is identical to the string quote of ALGOL 60. It has as wide a use as the <number>. Also, it will be seen later that com "a+b*D" is equivalent to 'a+b*D,c Pragmatics. A text literal is mapped and stored as a one-dimensional array. Justification. Needed to generate^ text. Examples; If a ^ fithen b-«-a+1.34; if a -^b 7^ «then display«-a else display*-"error in a"; displayHLf a-rb ^ »then a else "error in a" |
