let n be Nat; n -SuccRelStr is asymmetric
set S = n -SuccRelStr ;
the InternalRel of (n -SuccRelStr) is_asymmetric_in field the InternalRel of (n -SuccRelStr)
proof
let x,
y be
object ;
RELAT_2:def 5 ( not x in field the InternalRel of (n -SuccRelStr) or not y in field the InternalRel of (n -SuccRelStr) or not [x,y] in the InternalRel of (n -SuccRelStr) or not [y,x] in the InternalRel of (n -SuccRelStr) )
assume that
x in field the
InternalRel of
(n -SuccRelStr)
and
y in field the
InternalRel of
(n -SuccRelStr)
and A1:
[x,y] in the
InternalRel of
(n -SuccRelStr)
;
not [y,x] in the InternalRel of (n -SuccRelStr)
A2:
[x,y] in { [i,(i + 1)] where i is Element of NAT : i + 1 < n }
by A1, Def6;
assume
[y,x] in the
InternalRel of
(n -SuccRelStr)
;
contradiction
then
[y,x] in { [i9,(i9 + 1)] where i9 is Element of NAT : i9 + 1 < n }
by Def6;
then consider j being
Element of
NAT such that A3:
[y,x] = [j,(j + 1)]
and
j + 1
< n
;
A4:
(
y = j &
x = j + 1 )
by A3, XTUPLE_0:1;
consider i being
Element of
NAT such that A5:
[x,y] = [i,(i + 1)]
and
i + 1
< n
by A2;
(
x = i &
y = i + 1 )
by A5, XTUPLE_0:1;
hence
contradiction
by A4;
verum
end;
hence
the InternalRel of (n -SuccRelStr) is asymmetric
; NECKLACE:def 4 verum