set x = the Element of X;
set y = the Element of X \ { the Element of X};
( [ the Element of X, the Element of X] in id X & [ the Element of X \ { the Element of X}, the Element of X \ { the Element of X}] in id X ) by RELAT_1:def 10;
then A1: ( the Element of X in field (id X) & the Element of X \ { the Element of X} in field (id X) ) by RELAT_1:15;
not the Element of X \ { the Element of X} in { the Element of X} by XBOOLE_0:def 5;
then A2: the Element of X \ { the Element of X} <> the Element of X by TARSKI:def 1;
then ( not [ the Element of X, the Element of X \ { the Element of X}] in id X & not [ the Element of X \ { the Element of X}, the Element of X] in id X ) by RELAT_1:def 10;
hence not id X is connected by A1, A2, RELAT_2:def 6, RELAT_2:def 14; :: thesis: verum