not: function( old ){
      
      if( typeof old == 'object'  ) {
        
        old = old.elements || old, cur = this.elements;
        var temp = [], a = [], k = -1, el, key, c = 0;
        
        while( el = old[++k] ){
          key = el.tagName + el.id + el.className + el.name + el.style;
          if (temp[key]) { temp[key]++; } else { temp[key] = 1; }
        }
        
        k = -1;
        
        while( el = cur[++k] ){
          key = el.tagName + el.id + el.className + el.name + el.style;
          if (temp[key]) {
             if (temp[key] == 0) { return false; } else { temp[key]--; }
          } else
            a[c++] = el;
        }
      }
      
      return this.sync(a);
    }