find6 = function: bool
{
	x = [1, 2, 3, 4, 5, 6, 7]:  [num];  				//эффективная инициализация
	y = map (x) [el]-> {2 * el};
   
	exists(y, 12);
}

exists = function: (list:[a], el: a)->bool
{
	acc: bool;
	acc = reduce(list, false) [el, acc] -> 
	{
	  acc = acc & (el == e): saturated(true);
	}
}