1) permutations on sentences

{script
  var S_perm = function(a) {
    if (a.length < 2) return [a];
    var b = [];
    for (var c = 0; c < a.length; c++) {
        var e = a.splice(c, 1), f = S_perm(a);
        for (var d = 0; d < f.length; d++)
           b.push( e.concat( f[d]) );
        a.splice(c, 0, e[0])
    }
    return b
  }

  LAMBDATALK.DICT['S.perm'] = function() {  // {S.perm 1 2 3}
    return S_perm( arguments[0].trim()
                               .split(" ") )
                               .join(" ")
                               .replace(/\s/g,"{br}")
  };
}

{S.perm 1 2 3}
->
1,2,3
1,3,2
2,1,3
2,3,1
3,1,2
3,2,1

{S.perm hello brave world}
->
hello,brave,world
hello,world,brave
brave,hello,world
brave,world,hello
world,hello,brave
world,brave,hello

2) permutations on words

{script
  var W_perm = function(word) {
    if (word.length === 1) return [word]
    var results = [];
    for (var i = 0; i < word.length; i++) {
      var buti = W_perm( word.substring(0, i) + word.substring(i + 1) );
      for (var j = 0; j < buti.length; j++)
        results.push(word[i] + buti[j]);
    }
    return results;
  };

  LAMBDATALK.DICT['W.perm'] = function() {  // {W.perm 123}
    return W_perm( arguments[0].trim() ).join("{br}")
  };

}

{W.perm 123}
->
123
132
213
231
312
321