set R = value_of f;
thus
value_of f is antisymmetric
( value_of f is transitive & value_of f is beta-transitive )
thus
value_of f is transitive
value_of f is beta-transitive proof
let x be
set ;
MMLQUER2:def 1 for y, z being set st x,y in value_of f & y,z in value_of f holds
x,z in value_of flet y,
z be
set ;
( x,y in value_of f & y,z in value_of f implies x,z in value_of f )
assume
(
x,
y in value_of f &
y,
z in value_of f )
;
x,z in value_of f
then A1:
(
x in X &
z in X &
f . x < f . y &
f . y < f . z )
by Def5;
then
f . x < f . z
by XXREAL_0:2;
hence
x,
z in value_of f
by A1, Def5;
verum
end;
let x, y be Element of X; MMLQUER2:def 4 ( x,y nin value_of f implies for z being Element of X st x,z in value_of f holds
y,z in value_of f )
assume A2:
x,y nin value_of f
; for z being Element of X st x,z in value_of f holds
y,z in value_of f
let z be Element of X; ( x,z in value_of f implies y,z in value_of f )
assume
x,z in value_of f
; y,z in value_of f
then A3:
( x in X & f . x < f . z )
by Def5;
then
f . x >= f . y
by A2, Def5;
then
f . y < f . z
by A3, XXREAL_0:2;
hence
y,z in value_of f
by A3, Def5; verum