code: function winnow( elements, qualifier, not ) {
  	if ( isFunction( qualifier ) ) {
  		return jQuery.grep( elements, function( elem, i ) {
  			return !!qualifier.call( elem, i, elem ) !== not;
  		} );
  	}
  
  	// Single element
  	if ( qualifier.nodeType ) {
  		return jQuery.grep( elements, function( elem ) {
  			return ( elem === qualifier ) !== not;
  		} );
  	}
  
  	// Arraylike of elements (jQuery, arguments, Array)
  	if ( typeof qualifier !== "string" ) {
  		return jQuery.grep( elements, function( elem ) {
  			return ( indexOf.call( qualifier, elem ) > -1 ) !== not;
  		} );
  	}
  
  	// Filtered directly for both simple and complex selectors
  	return jQuery.filter( qualifier, elements, not );
  }
docs: Implement the identical functionality for filter and not