In some programming languages, an identifier is permitted to be a letter following by any number of letters or digits. If L and D denote the sets of letters and digits respectively, which of the following expressions defines an identifier?

Which of the following strings can definitely be said to be tokens without looking at the next input character while compiling a Pascal program?

I. begin
II. program
III. <>

A shift reduce parser carries out the actions specified within braces immediately after reducing with the corresponding rule of grammar.

$$\eqalign{ & S \to xxW\,\left\{ {pr{\mathop{\rm int}} \,'1'} \right\} \cr & S \to y\,\left\{ {pr{\mathop{\rm int}} \,'2'} \right\} \cr & W \to Sz\,\left\{ {pr{\mathop{\rm int}} \,'3'} \right\} \cr} $$

What is the translation of xxxxyzz using the syntax directed translation scheme described by the above rules?

A linker is given object modules for a set of programs that were compiled separately. What information need to be included in an object module?