old_contents: 
  export function* filterfalse ( predicate , iterable ) {
  
  	for ( let item of iterable ) {
  
  		if ( ! predicate( item ) ) yield item ;
  
  	}
  
  }
  
new_contents: /**
   * Yields all elements from input iterable that do not verify a given predicate.
   *
   * @example
   * // returns [ 0 , 2 , 4 , 6 , 8 ]
   * list( filter( x => x % 2 , range( 10 ) ) ) ;
   *
   * @param {Function} predicate - A unary function that returns a truthy or
   * falsy value.
   * @param {Iterable} iterable - The input iterable.
   * @returns {Iterator}
   *
   */
  export function* filterfalse ( predicate , iterable ) {
  
  	for ( let item of iterable ) {
  
  		if ( ! predicate( item ) ) yield item ;
  
  	}
  
  }
  
subject: document filterfalse