Substring ([s,e])
The [] (square
brackets) extract a substring.
Syntax
char-variable [ start  [, end  ] ] - char-variable must be a character data type variable.
 - start defines the position of the first character of the substring to be extracted.
 - end defines the position of the last character of the substring to be extracted.
 - If end is not specified, only one character is extracted.
 
Usage
The [] (square brackets)
notation following a CHAR or VARCHAR
variable extracts a substring from that character variable.
The start and end arguments can be expressed in bytes or characters, depending on the length semantics used in your programs.
Important: Substring
expressions in SQL statements are evaluated by the database server.
This may have a different behavior than the substring operator of
the language.
Example
MAIN
  DEFINE s CHAR(10)
  LET s = "abcdef"
  DISPLAY s[3,4]
END MAIN