let R be Relation; ( R is asymmetric implies R ~ is asymmetric )
assume
R is asymmetric
; R ~ is asymmetric
then A1:
R is_asymmetric_in field R
by Def13;
now let x,
y be
set ;
( x in field (R ~) & y in field (R ~) & [x,y] in R ~ implies not [y,x] in R ~ )assume that A2:
(
x in field (R ~) &
y in field (R ~) )
and A3:
[x,y] in R ~
;
not [y,x] in R ~ A4:
[y,x] in R
by A3, RELAT_1:def 7;
(
x in field R &
y in field R )
by A2, RELAT_1:21;
then
not
[x,y] in R
by A1, A4, Def5;
hence
not
[y,x] in R ~
by RELAT_1:def 7;
verum end;
then
R ~ is_asymmetric_in field (R ~)
by Def5;
hence
R ~ is asymmetric
by Def13; verum