the fact of being who or what a person or thing is
the characteristics determining who or what a person or thing is
(of an object) serving to establish who the holder, owner, or wearer is by bearing their name and often other details such as a signature or photograph
a close similarity or affinity
a transformation that leaves an object unchanged.
an element of a set which, if combined with another element by a specified binary operation, leaves that element unchanged.
the equality of two expressions for all values of the quantities expressed by letters, or an equation expressing this, e.g. (x + 1)² = x² + 2x + 1.