Proof for the following theorem:
  Every transitive(1), symmetric(2) and endless(3) relation is reflexive(4).


A x. A y. A z. (r(x,y) & r(y,z) -> r(x,z)) ;
A x. A y. (r(x,y) -> r(y,x)) ;
A x. E y. r(x,y) ;
~A x. r(x,x)