var cat = [ "Work on a String", "Replacement" ];
var titles = [
[   [ "Replace all matches of <i>PAT</i> in a file alternately with <i>OBJ<sub>1</sub></i> and <i>OBJ<sub>2</sub></i>.","p.20010216a" ],
   [ "Remove every group containing the specified member.","p.20100920a" ]],
[   [ "Replace every space character with an underscore in the first 8 characters of a line (string).","p.20001117b" ],
   [ "Replace every comma located between columns 10 thru 15 with a '#'.","p.20021011a" ],
   [ "Replace every third comma in a string with a newline.","p.20010115a" ],
   [ "Replace every 'B' in 1-byte-units with 'C', but retain those in 2-byte-units.","p.20010926a" ],
   [ "Replace every leading space of a line with a dot('.').","p.20031116a" ],
   [ "Replace every 8-digit integer not preceded by 'abc' with 'ABCDEFGH'.","p.20031120a" ],
   [ "Convert 'IP.port' to 'IP:port' in a file.","p.20040209a" ]],
[   [ "Replace every space character of every double-quoted string in a line with a dash('-').","p.20001115b" ],
   [ "Replace every comma NOT enclosed in a pair of double quotes with '|'.","p.20010228a" ],
   [ "Replace every non-escaped '@' with '#'. ","p.20050720a" ],
   [ "Replace every comma neither escaped nor enclosed in a pair of double quotes with '#'.","p.20050727a" ],
   [ "Remove members not beginning with <i>PAT</i> from lists.","p.20080708a" ],
   [ "Replace every comma(',') in a double-quoted string with a dash('-').","p.20080725a" ]],
[   [ "Increase a non-negative integer by 1.","p.20040503a" ]],
[   [ "Convert a sequence of one-byte codes into their corresponding actions.","p.20031128a" ],
   [ "Replace every matched string with a sequence of dashes of the same length.","p.20080117a" ],
   [ "Replace keys with associated values.","p.20080222a" ],
   [ "Remove the directory part of every path.","p.20080410a" ],
   [ "Find the shortest path to change directory from one to another.","p.20081231a" ],
   [ "Find the word preceding `!!' and delete all instances of that word.","p.20090723a" ]]];
var subcat = [ "Every match", "Some Matches of <i>PAT</i> in a line.", "Matches of <i>PAT</i> (not) escaped or inside quotes.", "Numbers-related", "Misc." ];