set is an element that are gathered together becouse they have intersection properties that bind them together.
set must have certain rule, so it can be "set" into some set.
set no need to be exactly their elemnt to be equal, but at least the possessed the rule that bound them all.
set may be differ due to the rule or principle that built them.
set must have a subset, properties of set, follow the operation of set, compliment.
set are generalization of specific elemetn,.. but in universal set it will become specific .
human is a set of uncertainity..