let n be Element of NAT ; :: thesis: for o being TermOrder of n st o is admissible holds
( the InternalRel of (NaivelyOrderedBags n) c= o & o is well-ordering )
let o be TermOrder of n; :: thesis: ( o is admissible implies ( the InternalRel of (NaivelyOrderedBags n) c= o & o is well-ordering ) )
assume A1:
o is admissible
; :: thesis: ( the InternalRel of (NaivelyOrderedBags n) c= o & o is well-ordering )
set IRN = the InternalRel of (NaivelyOrderedBags n);
now let a,
b be
set ;
:: thesis: ( [a,b] in the InternalRel of (NaivelyOrderedBags n) implies [a,b] in o )assume A2:
[a,b] in the
InternalRel of
(NaivelyOrderedBags n)
;
:: thesis: [a,b] in o
(
a in dom the
InternalRel of
(NaivelyOrderedBags n) &
b in rng the
InternalRel of
(NaivelyOrderedBags n) )
by A2, RELAT_1:20;
then reconsider a1 =
a,
b1 =
b as
Element of
Bags n by Def13;
A3:
a1 divides b1
by A2, Def13;
set l =
b1 -' a1;
then A5:
(b1 -' a1) + a1 = b1
by PBOOLE:3;
[(EmptyBag n),(b1 -' a1)] in o
by A1, Def7;
then
[((EmptyBag n) + a1),((b1 -' a1) + a1)] in o
by A1, Def7;
hence
[a,b] in o
by A5, POLYNOM1:57;
:: thesis: verum end;
hence A6:
the InternalRel of (NaivelyOrderedBags n) c= o
by RELAT_1:def 3; :: thesis: o is well-ordering
set R = product (n --> OrderedNAT );
set S = RelStr(# (Bags n),o #);
A7:
RelStr(# (Bags n),o #) is quasi_ordered
by DICKSON:def 3;
A8:
the InternalRel of (product (n --> OrderedNAT )) c= the InternalRel of RelStr(# (Bags n),o #)
by A6, Th34;
the carrier of (product (n --> OrderedNAT )) = the carrier of RelStr(# (Bags n),o #)
by Th33;
then A9:
RelStr(# (Bags n),o #) \~ is well_founded
by A7, A8, DICKSON:50;
hence
o is well-ordering
by WELLORD1:def 4; :: thesis: verum