$ include "seed7_05.s7i";
  include "gethttp.s7i";

const func string: reverse (in string: word) is func
  result
    var string: drow is "";
  local
    var integer: index is 0;
  begin
    for index range length(word) downto 1 do
      drow &:= word[index];
    end for;
  end func;

const proc: main is func
  local
    var array string: wordList is 0 times "";
    var set of string: words is (set of string).value;
    var string: word is "";
    var string: drow is "";
    var integer: count is 0;
  begin
    wordList := split(lower(getHttp("www.puzzlers.org/pub/wordlists/unixdict.txt")), "\n");
    for word range wordList do
      drow := reverse(word);
      if drow not in words then
        incl(words, word);
      else
        if count < 5 then
          writeln(word <& " " <& drow);
        end if;
        incr(count);
      end if;
    end for;
    writeln;
    writeln("Semordnilap pairs: " <& count);
  end func;