let L be lower-bounded sup-Semilattice; :: thesis: for AR being auxiliary(i) auxiliary(ii) Relation of L holds AR is transitive
let AR be auxiliary(i) auxiliary(ii) Relation of L; :: thesis: AR is transitive
A1:
field AR c= the carrier of L \/ the carrier of L
by RELSET_1:19;
now let x,
y,
z be
set ;
:: thesis: ( x in field AR & y in field AR & z in field AR & [x,y] in AR & [y,z] in AR implies [x,z] in AR )assume that A2:
x in field AR
and A3:
y in field AR
and A4:
z in field AR
and A5:
[x,y] in AR
and A6:
[y,z] in AR
;
:: thesis: [x,z] in ARreconsider x' =
x,
y' =
y,
z' =
z as
Element of
L by A1, A2, A3, A4;
reconsider x' =
x',
y' =
y',
z' =
z' as
Element of
L ;
A7:
x' <= y'
by A5, Def4;
z' <= z'
;
hence
[x,z] in AR
by A6, A7, Def5;
:: thesis: verum end;
then
AR is_transitive_in field AR
by RELAT_2:def 8;
hence
AR is transitive
by RELAT_2:def 16; :: thesis: verum