thus A1:
{} is reflexive
ORDERS_1:def 3 ( {} is transitive & {} is being_partial-order & {} is being_linear-order & {} is well-ordering )
thus A2:
{} is transitive
( {} is being_partial-order & {} is being_linear-order & {} is well-ordering )proof
let x be
set ;
RELAT_2:def 8,
RELAT_2:def 16 for b1, b2 being set holds
( not x in field {} or not b1 in field {} or not b2 in field {} or not [x,b1] in {} or not [b1,b2] in {} or [x,b2] in {} )let y,
z be
set ;
( not x in field {} or not y in field {} or not z in field {} or not [x,y] in {} or not [y,z] in {} or [x,z] in {} )
assume
x in field {}
;
( not y in field {} or not z in field {} or not [x,y] in {} or not [y,z] in {} or [x,z] in {} )
thus
( not
y in field {} or not
z in field {} or not
[x,y] in {} or not
[y,z] in {} or
[x,z] in {} )
;
verum
end;
hence
( {} is reflexive & {} is transitive )
by A1; ORDERS_1:def 4 ( {} is antisymmetric & {} is being_linear-order & {} is well-ordering )
thus A3:
{} is antisymmetric
( {} is being_linear-order & {} is well-ordering )
hence
( {} is reflexive & {} is transitive & {} is antisymmetric )
by A1, A2; ORDERS_1:def 5 ( {} is connected & {} is well-ordering )
thus
{} is connected
{} is well-ordering
hence
( {} is reflexive & {} is transitive & {} is antisymmetric & {} is connected )
by A1, A2, A3; WELLORD1:def 4 {} is well_founded
let Y be set ; WELLORD1:def 2 ( not Y c= field {} or Y = {} or ex b1 being set st
( b1 in Y & {} -Seg b1 misses Y ) )
assume that
A4:
Y c= field {}
and
A5:
Y <> {}
; ex b1 being set st
( b1 in Y & {} -Seg b1 misses Y )
thus
ex b1 being set st
( b1 in Y & {} -Seg b1 misses Y )
by A4, A5; verum