Suppose X is a non-empty finite set, and is a binary operation on which is associative i.e. (x.y).z=x.(y.z) for all x,y,z, in z . Show that there is an element x in x such that x.x=x .
Suppose X is a non-empty finite set, and is a binary operation on which is associative i.e. (x.y).z=x.(y.z) for all x,y,z, in z . Show that there is an element x in x such that x.x=x .
