(1) X=Y                         ; Given
(2) X^2=XY                      ; Multiply both sides by X
(3) X^2-Y^2=XY-Y^2              ; Subtract Y^2 from both sides
(4) (X+Y)(X-Y)=Y(X-Y)           ; Factor
(5) X+Y=Y                       ; Cancel out (X-Y) term
(6) 2Y=Y                        ; Substitute X for Y, by equation 1
(7) 2=1                         ; Divide both sides by Y

   -- "Omni", proof that 2 equals 1