let IT1, IT2 be TermOrder of n; ( ( for a, b being bag of n holds
( [a,b] in IT1 iff ( TotDegree a < TotDegree b or ( TotDegree a = TotDegree b & [a,b] in o ) ) ) ) & ( for a, b being bag of n holds
( [a,b] in IT2 iff ( TotDegree a < TotDegree b or ( TotDegree a = TotDegree b & [a,b] in o ) ) ) ) implies IT1 = IT2 )
assume that
A36:
for a, b being bag of n holds
( [a,b] in IT1 iff ( TotDegree a < TotDegree b or ( TotDegree a = TotDegree b & [a,b] in o ) ) )
and
A37:
for a, b being bag of n holds
( [a,b] in IT2 iff ( TotDegree a < TotDegree b or ( TotDegree a = TotDegree b & [a,b] in o ) ) )
; IT1 = IT2
now for a, b being object holds
( ( [a,b] in IT1 implies [a,b] in IT2 ) & ( [a,b] in IT2 implies [a,b] in IT1 ) )let a,
b be
object ;
( ( [a,b] in IT1 implies [a,b] in IT2 ) & ( [a,b] in IT2 implies [a,b] in IT1 ) )hereby ( [a,b] in IT2 implies [a,b] in IT1 )
end; assume A40:
[a,b] in IT2
;
[a,b] in IT1then A41:
a in dom IT2
by XTUPLE_0:def 12;
b in rng IT2
by A40, XTUPLE_0:def 13;
then reconsider a9 =
a,
b9 =
b as
bag of
n by A41;
(
TotDegree a9 < TotDegree b9 or (
TotDegree a9 = TotDegree b9 &
[a9,b9] in o ) )
by A37, A40;
hence
[a,b] in IT1
by A36;
verum end;
hence
IT1 = IT2
by RELAT_1:def 2; verum