LINE_BEGIN
     Returns a pattern that matches the beginning-of-line condition.
  Syntax
     pattern := LINE_BEGIN
  Comments
     LINE_BEGIN is a keyword, not a built-in procedure.  However, it is used
     like a built-in to construct patterns.
  Example
     The following procedure erases all RUNOFF commands from a file by
     searching for a pattern that has a period (.) at the beginning of a
     line and then erasing the lines that match this condition:
     PROCEDURE user_delete_runoff_lines
        LOCAL search_runoff, pattern_runoff;
        pattern_runoff := LINE_BEGIN + ".";
        LOOP
           search_runoff := SEARCH (pattern_runoff, FORWARD);
           EXITIF sear1 = 0;
           POSITION (search_runoff);
           ERASE_LINE;
        ENDLOOP;
     ENDPROCEDURE;
  Related topics
     BEGINNING_OF    LINE_END