let R be finite transitive antisymmetric RelStr ; for r, s being Nat holds
( not card R = (r * s) + 1 or ex C being Clique of R st card C >= r + 1 or ex A being StableSet of R st card A >= s + 1 )
let r, s be Nat; ( not card R = (r * s) + 1 or ex C being Clique of R st card C >= r + 1 or ex A being StableSet of R st card A >= s + 1 )
assume that
A:
card R = (r * s) + 1
and
B:
for C being Clique of R holds card C < r + 1
and
C:
for A being StableSet of R holds card A < s + 1
; contradiction
consider p being Clique-partition of R such that
D:
card p = stability# R
by DWf;
consider A being finite StableSet of R such that
E:
card A = stability# R
by Lwidth;
stability# R < s + 1
by C, E;
then Fa:
stability# R <= s
by NAT_1:13;
set wR = stability# R;
set cR = the carrier of R;
set f = canFS p;
Fb:
len (canFS p) = card p
by UPROOTS:5;
Fd:
dom (canFS p) = Seg (len (canFS p))
by FINSEQ_1:def 3;
set f = canFS p;
G:
rng (canFS p) = p
by FUNCT_2:def 3;
then reconsider f = canFS p as FinSequence of bool the carrier of R by FINSEQ_1:def 4;
now let d,
e be
Nat;
( d in dom f & e in dom f & d <> e implies f . d misses f . e )assume that A2:
d in dom f
and B2:
e in dom f
and C2:
d <> e
;
f . d misses f . eD2:
f . d in rng f
by A2, FUNCT_1:12;
E2:
f . e in rng f
by B2, FUNCT_1:12;
then reconsider fd =
f . d,
fe =
f . e as
Subset of the
carrier of
R by D2, G;
fd <> fe
by C2, A2, B2, FUNCT_1:def 8;
hence
f . d misses f . e
by D2, E2, G, EQREL_1:def 6;
verum end;
then I:
card (union (rng f)) = Sum (Card f)
by Fb, INT_5:48;
reconsider n9 = r as Element of NAT by ORDINAL1:def 13;
reconsider h = (stability# R) |-> n9 as Element of (stability# R) -tuples_on NAT by FINSEQ_2:132;
Ia:
Sum h = (stability# R) * r
by RVSUM_1:110;
dom f = dom (Card f)
by CARD_3:def 2;
then
len (Card f) = stability# R
by Fb, D, FINSEQ_3:31;
then reconsider Cf = Card f as Element of (stability# R) -tuples_on NAT by FINSEQ_2:110;
Ic:
h is Element of (stability# R) -tuples_on REAL
by FINSEQ_2:129;
Ie:
Cf is Element of (stability# R) -tuples_on REAL
by FINSEQ_2:129;
now let j be
Nat;
( j in Seg (stability# R) implies Cf . j <= h . j )assume A2:
j in Seg (stability# R)
;
Cf . j <= h . jB2:
h . j = r
by A2, FINSEQ_2:71;
C2:
Cf . j = card (f . j)
by A2, Fb, Fd, D, CARD_3:def 2;
f . j in p
by G, A2, D, Fb, Fd, FUNCT_1:12;
then reconsider fj =
f . j as
Clique of
R by LCpart;
card fj < r + 1
by B;
hence
Cf . j <= h . j
by B2, C2, NAT_1:13;
verum end;
then bI:
Sum Cf <= Sum h
by Ic, Ie, RVSUM_1:112;
(stability# R) * r <= s * r
by Fa, XREAL_1:66;
then
Sum Cf <= s * r
by Ia, bI, XXREAL_0:2;
then
(r * s) + 1 <= (r * s) + 0
by I, G, A, EQREL_1:def 6;
hence
contradiction
by XREAL_1:8; verum