ex x being object st
( x in field [:X,X:] & [x,x] in [:X,X:] )
proof
consider x being
object such that A3:
x in X
by XBOOLE_0:def 1;
take
x
;
( x in field [:X,X:] & [x,x] in [:X,X:] )
field [:X,X:] = X \/ X
by WELLSET1:2;
hence
x in field [:X,X:]
by A3;
[x,x] in [:X,X:]
thus
[x,x] in [:X,X:]
by A3, ZFMISC_1:def 2;
verum
end;
hence
( not [:X,X:] is irreflexive & not [:X,X:] is asymmetric )
by RELAT_2:def 2, RELAT_2:def 10; verum