var det = M.elements[0][0], n = M.elements.length - 1, k = n, i; do { i = k - n + 1; 
var det = M.elements[0][0], n = M.elements.length; for (var i = 1; i < n; i++) { 
  determinant: function() {    if (!this.isSquare()) { return null; }    var M = this.toRightTriangular();    var det = M.elements[0][0], n = M.elements.length - 1, k = n, i;    do { i = k - n + 1;      det = det * M.elements[i][i];    } while (--n);    return det;  },
3123	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/3123/5bb35ddb3516d7e68f3747d86540ffaa68de3fe3/matrix.js/buggy/src/matrix.js