:: Some Properties for Convex Combinations
:: by Noboru Endou , Yasumasa Suzuki and Yasunari Shidama
::
:: Received April 3, 2003
:: Copyright (c) 2003-2018 Association of Mizar Users
:: (Stowarzyszenie Uzytkownikow Mizara, Bialystok, Poland).
:: This code can be distributed under the GNU General Public Licence
:: version 3.0 or later, or the Creative Commons Attribution-ShareAlike
:: License version 3.0 or later, subject to the binding interpretation
:: detailed in file COPYING.interpretation.
:: See COPYING.GPL and COPYING.CC-BY-SA for the full text of these
:: licenses, or see http://www.gnu.org/licenses/gpl.html and
:: http://creativecommons.org/licenses/by-sa/3.0/.
environ
vocabularies NUMBERS, REAL_1, FINSEQ_1, XBOOLE_0, RLVECT_1, CONVEX1, SUBSET_1,
BHSP_1, STRUCT_0, RELAT_1, FUNCT_1, PROB_2, XXREAL_0, CARD_1, ARYTM_3,
ARYTM_1, RLVECT_2, TARSKI, CARD_3, NAT_1, VALUED_1, JORDAN3, PARTFUN1,
ORDINAL4, FUNCT_2, RLSUB_1, RUSUB_4, CLASSES1, FINSET_1, CONVEX2,
FUNCT_7, XCMPLX_0;
notations TARSKI, XBOOLE_0, SUBSET_1, CARD_1, ORDINAL1, NUMBERS, XCMPLX_0,
XXREAL_0, XREAL_0, REAL_1, RELAT_1, FUNCT_1, PARTFUN1, FUNCT_2, FINSET_1,
NAT_1, FINSEQ_1, DOMAIN_1, STRUCT_0, ALGSTR_0, RLVECT_1, RLSUB_1,
RLSUB_2, FINSEQ_4, RLVECT_2, RVSUM_1, BHSP_1, RUSUB_4, CONVEX1, FINSEQ_6,
CLASSES1;
constructors WELLORD2, DOMAIN_1, REAL_1, BINOP_2, FINSEQ_4, FINSOP_1, RLSUB_2,
RUSUB_4, CONVEX1, MATRIX_1, FINSEQ_6, RVSUM_1, CLASSES1, RELSET_1,
NUMBERS;
registrations XBOOLE_0, RELAT_1, FUNCT_1, NUMBERS, XXREAL_0, NAT_1, FINSEQ_1,
STRUCT_0, RLVECT_1, RUSUB_4, CONVEX1, VALUED_0, RELSET_1, RLVECT_2,
XREAL_0, ORDINAL1, RVSUM_1, CARD_1;
requirements REAL, NUMERALS, SUBSET, BOOLE, ARITHM;
definitions TARSKI, CONVEX1;
equalities FINSEQ_1, RVSUM_1;
expansions TARSKI, CONVEX1;
theorems BHSP_1, RLVECT_1, RVSUM_1, FUNCT_1, FINSEQ_1, TARSKI, ZFMISC_1,
XBOOLE_0, RUSUB_4, XBOOLE_1, RLVECT_2, CARD_1, FINSEQ_3, FINSEQ_4,
ENUMSET1, CONVEX1, PARTFUN1, FINSEQ_6, RLSUB_2, FUNCT_2, NAT_1, FVSUM_1,
RFINSEQ, FINSET_1, INTEGRA5, XCMPLX_1, XREAL_1, XXREAL_0, FINSOP_1,
STRUCT_0, VALUED_1, CLASSES1, RLVECT_4, XREAL_0;
schemes NAT_1, XBOOLE_0, FINSEQ_1, CLASSES1;
begin :: Convex Combination on Convex Family
reconsider rr = 1 as Element of REAL by XREAL_0:def 1;
set ff = <*rr*>;
theorem
for V being non empty RLSStruct, M,N being convex Subset of V holds M
/\ N is convex;
theorem
for V being RealUnitarySpace-like non empty UNITSTR, M being Subset
of V, F being FinSequence of the carrier of V, B being FinSequence of REAL st M
= {u where u is VECTOR of V : for i being Element of NAT st i in (dom F /\ dom
B) holds ex v being VECTOR of V st v = F.i & u .|. v <= B.i} holds M is convex
proof
let V be RealUnitarySpace-like non empty UNITSTR;
let M be Subset of V;
let F be FinSequence of the carrier of V;
let B be FinSequence of REAL;
assume
A1: M = {u where u is VECTOR of V: for i being Element of NAT st i in (
dom F /\ dom B) holds ex v being VECTOR of V st v = F.i & u.|.v <= B.i};
let u1,v1 be VECTOR of V;
let r be Real;
assume that
A2: 0 < r and
A3: r < 1 and
A4: u1 in M and
A5: v1 in M;
consider v9 be VECTOR of V such that
A6: v1 = v9 and
A7: for i being Element of NAT st i in (dom F /\ dom B) holds ex v being
VECTOR of V st v = F.i & v9.|.v <= B.i by A1,A5;
consider u9 be VECTOR of V such that
A8: u1 = u9 and
A9: for i being Element of NAT st i in (dom F /\ dom B) holds ex v being
VECTOR of V st v = F.i & u9.|.v <= B.i by A1,A4;
for i being Element of NAT st i in (dom F /\ dom B) holds ex v being
VECTOR of V st v = F.i & (r*u1 + (1-r)*v1).|.v <= B.i
proof
0 + r < 1 by A3;
then
A10: 1 - r > 0 by XREAL_1:20;
let i be Element of NAT;
assume
A11: i in dom F /\ dom B;
reconsider b = B.i as Real;
consider x being VECTOR of V such that
A12: x = F.i and
A13: u9.|. x <= b by A9,A11;
take v = x;
A14: (r*u1 + (1-r)*v1).|.v = (r*u1).|.v + ((1-r)*v1).|.v by BHSP_1:def 2
.= r*(u1.|.v) + ((1-r)*v1).|.v by BHSP_1:def 2
.= r*(u1.|.v) + (1-r)*(v1.|.v) by BHSP_1:def 2;
r*(u1.|.v) <= r*b by A2,A8,A13,XREAL_1:64;
then (r*u1 + (1-r)*v1).|.v <= r * b + (1-r)*(v1.|.v) by A14,XREAL_1:6;
then
A15: (r*u1 + (1-r)*v1).|.v - r * b <= (1-r)*(v1.|.v) by XREAL_1:20;
ex y being VECTOR of V st y = F.i & v9.|. y <= b by A7,A11;
then (1-r)*(v1.|.v) <= (1-r)*b by A6,A12,A10,XREAL_1:64;
then (r*u1 + (1-r)*v1).|.v - r * b <= (1-r)*b by A15,XXREAL_0:2;
then (r*u1 + (1-r)*v1).|.v <= r * b + (1-r)*b by XREAL_1:20;
hence thesis by A12;
end;
hence thesis by A1;
end;
theorem
for V being RealUnitarySpace-like non empty UNITSTR, M being Subset
of V, F being FinSequence of the carrier of V, B being FinSequence of REAL st M
= {u where u is VECTOR of V : for i being Element of NAT st i in (dom F /\ dom
B) holds ex v being VECTOR of V st v = F.i & u .|. v < B.i} holds M is convex
proof
let V be RealUnitarySpace-like non empty UNITSTR;
let M be Subset of V;
let F be FinSequence of the carrier of V;
let B be FinSequence of REAL;
assume
A1: M = {u where u is VECTOR of V: for i being Element of NAT st i in (
dom F /\ dom B) holds ex v being VECTOR of V st v = F.i & u.|.v < B.i};
let u1,v1 be VECTOR of V;
let r be Real;
assume that
A2: 0 < r and
A3: r < 1 and
A4: u1 in M and
A5: v1 in M;
consider v9 be VECTOR of V such that
A6: v1 = v9 and
A7: for i being Element of NAT st i in (dom F /\ dom B) holds ex v being
VECTOR of V st v = F.i & v9.|.v < B.i by A1,A5;
consider u9 be VECTOR of V such that
A8: u1 = u9 and
A9: for i being Element of NAT st i in (dom F /\ dom B) holds ex v being
VECTOR of V st v = F.i & u9.|.v < B.i by A1,A4;
for i being Element of NAT st i in (dom F /\ dom B) holds ex v being
VECTOR of V st v = F.i & (r*u1 + (1-r)*v1).|.v < B.i
proof
0 + r < 1 by A3;
then
A10: 1 - r > 0 by XREAL_1:20;
let i be Element of NAT;
assume
A11: i in (dom F /\ dom B);
reconsider b = B.i as Real;
consider x being VECTOR of V such that
A12: x = F.i and
A13: u9.|. x < b by A9,A11;
take v = x;
A14: (r*u1 + (1-r)*v1).|.v = (r*u1).|.v + ((1-r)*v1).|.v by BHSP_1:def 2
.= r*(u1.|.v) + ((1-r)*v1).|.v by BHSP_1:def 2
.= r*(u1.|.v) + (1-r)*(v1.|.v) by BHSP_1:def 2;
r*(u1.|.v) < r*b by A2,A8,A13,XREAL_1:68;
then (r*u1 + (1-r)*v1).|.v < r * b + (1-r)*(v1.|.v) by A14,XREAL_1:8;
then
A15: (r*u1 + (1-r)*v1).|.v - r * b < (1-r)*(v1.|.v) by XREAL_1:19;
ex y being VECTOR of V st y = F.i & v9.|. y < b by A7,A11;
then (1-r)*(v1.|.v) <= (1-r)*b by A6,A12,A10,XREAL_1:64;
then (r*u1 + (1-r)*v1).|.v - r * b < (1-r)*b by A15,XXREAL_0:2;
then (r*u1 + (1-r)*v1).|.v < r * b + (1-r)*b by XREAL_1:19;
hence thesis by A12;
end;
hence thesis by A1;
end;
theorem
for V being RealUnitarySpace-like non empty UNITSTR, M being Subset
of V, F being FinSequence of the carrier of V, B being FinSequence of REAL st M
= {u where u is VECTOR of V : for i being Element of NAT st i in (dom F /\ dom
B) holds ex v being VECTOR of V st v = F.i & u .|. v >= B.i} holds M is convex
proof
let V be RealUnitarySpace-like non empty UNITSTR;
let M be Subset of V;
let F be FinSequence of the carrier of V;
let B be FinSequence of REAL;
assume
A1: M = {u where u is VECTOR of V: for i being Element of NAT st i in (
dom F /\ dom B) holds ex v being VECTOR of V st v = F.i & u.|.v >= B.i};
let u1,v1 be VECTOR of V;
let r be Real;
assume that
A2: 0 < r and
A3: r < 1 and
A4: u1 in M and
A5: v1 in M;
consider v9 be VECTOR of V such that
A6: v1 = v9 and
A7: for i being Element of NAT st i in (dom F /\ dom B) holds ex v being
VECTOR of V st v = F.i & v9.|.v >= B.i by A1,A5;
consider u9 be VECTOR of V such that
A8: u1 = u9 and
A9: for i being Element of NAT st i in (dom F /\ dom B) holds ex v being
VECTOR of V st v = F.i & u9.|.v >= B.i by A1,A4;
for i being Element of NAT st i in (dom F /\ dom B) holds ex v being
VECTOR of V st v = F.i & (r*u1 + (1-r)*v1).|.v >= B.i
proof
0 + r < 1 by A3;
then
A10: 1 - r > 0 by XREAL_1:20;
let i be Element of NAT;
assume
A11: i in (dom F /\ dom B);
reconsider b = B.i as Real;
consider x being VECTOR of V such that
A12: x = F.i and
A13: u9.|. x >= b by A9,A11;
take v = x;
A14: (r*u1 + (1-r)*v1).|.v = (r*u1).|.v + ((1-r)*v1).|.v by BHSP_1:def 2
.= r*(u1.|.v) + ((1-r)*v1).|.v by BHSP_1:def 2
.= r*(u1.|.v) + (1-r)*(v1.|.v) by BHSP_1:def 2;
r*(u1.|.v) >= r*b by A2,A8,A13,XREAL_1:64;
then (r*u1 + (1-r)*v1).|.v >= r * b + (1-r)*(v1.|.v) by A14,XREAL_1:6;
then
A15: (r*u1 + (1-r)*v1).|.v - r * b >= (1-r)*(v1.|.v) by XREAL_1:19;
ex y being VECTOR of V st y = F.i & v9.|. y >= b by A7,A11;
then (1-r)*(v1.|.v) >= (1-r)*b by A6,A12,A10,XREAL_1:64;
then (r*u1 + (1-r)*v1).|.v - r * b >= (1-r)*b by A15,XXREAL_0:2;
then (r*u1 + (1-r)*v1).|.v >= r * b + (1-r)*b by XREAL_1:19;
hence thesis by A12;
end;
hence thesis by A1;
end;
theorem
for V being RealUnitarySpace-like non empty UNITSTR, M being Subset
of V, F being FinSequence of the carrier of V, B being FinSequence of REAL st M
= {u where u is VECTOR of V : for i being Element of NAT st i in (dom F /\ dom
B) holds ex v being VECTOR of V st v = F.i & u .|. v > B.i} holds M is convex
proof
let V be RealUnitarySpace-like non empty UNITSTR;
let M be Subset of V;
let F be FinSequence of the carrier of V;
let B be FinSequence of REAL;
assume
A1: M = {u where u is VECTOR of V: for i being Element of NAT st i in (
dom F /\ dom B) holds ex v being VECTOR of V st v = F.i & u.|.v > B.i};
let u1,v1 be VECTOR of V;
let r be Real;
assume that
A2: 0 < r and
A3: r < 1 and
A4: u1 in M and
A5: v1 in M;
consider v9 be VECTOR of V such that
A6: v1 = v9 and
A7: for i being Element of NAT st i in (dom F /\ dom B) holds ex v being
VECTOR of V st v = F.i & v9.|.v > B.i by A1,A5;
consider u9 be VECTOR of V such that
A8: u1 = u9 and
A9: for i being Element of NAT st i in (dom F /\ dom B) holds ex v being
VECTOR of V st v = F.i & u9.|.v > B.i by A1,A4;
for i being Element of NAT st i in (dom F /\ dom B) holds ex v being
VECTOR of V st v = F.i & (r*u1 + (1-r)*v1).|.v > B.i
proof
0 + r < 1 by A3;
then
A10: 1 - r > 0 by XREAL_1:20;
let i be Element of NAT;
assume
A11: i in (dom F /\ dom B);
reconsider b = B.i as Real;
consider x being VECTOR of V such that
A12: x = F.i and
A13: u9.|. x > b by A9,A11;
take v = x;
A14: (r*u1 + (1-r)*v1).|.v = (r*u1).|.v + ((1-r)*v1).|.v by BHSP_1:def 2
.= r*(u1.|.v) + ((1-r)*v1).|.v by BHSP_1:def 2
.= r*(u1.|.v) + (1-r)*(v1.|.v) by BHSP_1:def 2;
r*(u1.|.v) > r*b by A2,A8,A13,XREAL_1:68;
then (r*u1 + (1-r)*v1).|.v > r * b + (1-r)*(v1.|.v) by A14,XREAL_1:8;
then
A15: (r*u1 + (1-r)*v1).|.v - r * b > (1-r)*(v1.|.v) by XREAL_1:20;
ex y being VECTOR of V st y = F.i & v9.|. y > b by A7,A11;
then (1-r)*(v1.|.v) >= (1-r)*b by A6,A12,A10,XREAL_1:64;
then (r*u1 + (1-r)*v1).|.v - r * b > (1-r)*b by A15,XXREAL_0:2;
then (r*u1 + (1-r)*v1).|.v > r * b + (1-r)*b by XREAL_1:20;
hence thesis by A12;
end;
hence thesis by A1;
end;
Lm1: for V being RealLinearSpace, M being convex Subset of V holds for N being
Subset of V, L being Linear_Combination of N st L is convex & N c= M holds Sum(
L) in M
proof
let V be RealLinearSpace;
let M be convex Subset of V;
let N be Subset of V;
let L be Linear_Combination of N;
assume that
A1: L is convex and
A2: N c= M;
consider F being FinSequence of the carrier of V such that
A3: F is one-to-one and
A4: rng F = Carrier L and
A5: ex f being FinSequence of REAL st len f = len F & Sum(f) = 1 & for n
being Nat st n in dom f holds f.n = L.(F.n) & f.n >= 0 by A1;
consider f being FinSequence of REAL such that
A6: len f = len F and
A7: Sum(f) = 1 and
A8: for n being Nat st n in dom f holds f.n = L.(F.n) & f.n >= 0 by A5;
not Carrier(L),{} are_equipotent by A1,CARD_1:26,CONVEX1:21;
then
A9: card(Carrier(L)) <> card {} by CARD_1:5;
then reconsider i = len F as non zero Element of NAT by A3,A4,FINSEQ_4:62;
A10: len (L (#) F) = len F by RLVECT_2:def 7;
defpred P[Nat] means (1/Sum(mid(f,1,$1)))*Sum(mid(L(#)F,1,$1)) in M;
A11: len (L(#)F) = len F by RLVECT_2:def 7;
A12: for k being non zero Nat st P[k] holds P[k+1]
proof
let k be non zero Nat;
A13: k >= 1 by NAT_1:14;
assume
A14: (1/Sum(mid(f,1,k)))*Sum(mid(L(#)F,1,k)) in M;
now
per cases;
suppose
A15: k >= len f;
A16: mid(L(#)F,1,k+1) = (L(#)F)|(k+1) by FINSEQ_6:116,NAT_1:12
.= L(#)F by A6,A11,A15,FINSEQ_1:58,NAT_1:12;
A17: mid(f,1,k) = f|k by FINSEQ_6:116,NAT_1:14
.= f by A15,FINSEQ_1:58;
A18: mid(f,1,k+1) = f|(k+1) by FINSEQ_6:116,NAT_1:12
.= f by A15,FINSEQ_1:58,NAT_1:12;
mid(L(#)F,1,k) = (L(#)F)|k by FINSEQ_6:116,NAT_1:14
.= L(#)F by A6,A11,A15,FINSEQ_1:58;
hence thesis by A14,A17,A18,A16;
end;
suppose
A19: k < len f;
mid(f,1,k) = f|k by FINSEQ_6:116,NAT_1:14;
then
A20: len mid(f,1,k) = k by A19,FINSEQ_1:59;
A21: ex i being Element of NAT st i in dom mid(f,1,k) & 0 < mid(f,1,k ).i
proof
take 1;
1 <= len f by A19,NAT_1:14;
then
A22: 1 in Seg len f;
then 1 in dom f by FINSEQ_1:def 3;
then
A23: f.1 = L.(F.1) & f.1 >= 0 by A8;
1 in dom F by A6,A22,FINSEQ_1:def 3;
then F.1 in Carrier(L) by A4,FUNCT_1:def 3;
then F.1 in {v where v is Element of V : L.v <> 0} by RLVECT_2:def 4;
then
A24: ex v being Element of V st v = F.1 & L.v <> 0;
1 in Seg len mid(f,1,k) by A13,A20;
hence thesis by A13,A19,A23,A24,FINSEQ_1:def 3,FINSEQ_6:123;
end;
A25: for i being Nat st i in dom <* mid(f,1,k+1).(k+1) *> holds mid(f,
1,k+1).(len mid(f,1,k) + i) = <* mid(f,1,k+1).(k+1) *>.i
proof
let i be Nat;
assume i in dom <* mid(f,1,k+1).(k+1) *>;
then i in Seg 1 by FINSEQ_1:38;
then i = 1 by FINSEQ_1:2,TARSKI:def 1;
hence thesis by A20,FINSEQ_1:40;
end;
A26: mid(f,1,k+1) = f|(k+1) by FINSEQ_6:116,NAT_1:14;
set r1 = Sum(mid(f,1,k));
for i being Nat st i in dom mid(f,1,k) holds 0 <= mid(f,1,k).i
proof
let i be Nat;
assume i in dom mid(f,1,k);
then
A27: i in Seg k by A20,FINSEQ_1:def 3;
then
A28: 1 <= i by FINSEQ_1:1;
A29: i <= k by A27,FINSEQ_1:1;
then i <= len f by A19,XXREAL_0:2;
then
A30: i in dom f by A28,FINSEQ_3:25;
mid(f,1,k).i = f.i by A19,A28,A29,FINSEQ_6:123;
hence thesis by A8,A30;
end;
then
A31: r1 > 0 by A21,RVSUM_1:85;
A32: k+1 <= len f by A19,NAT_1:13;
then
A33: len (f|(k+1)) = k+1 by FINSEQ_1:59;
A34: for i being Nat st i in dom mid(f,1,k) holds mid(f,1,k+1).i = mid
(f,1,k).i
proof
let i be Nat;
A35: mid(f,1,k) = f|k by FINSEQ_6:116,NAT_1:14;
assume
A36: i in dom mid(f,1,k);
then
A37: i in Seg len(f|k) by A35,FINSEQ_1:def 3;
len(f|k) = k by A19,FINSEQ_1:59;
then i <= k by A37,FINSEQ_1:1;
then
A38: i <= k+1 by NAT_1:12;
(f|k).i = (f|k)/.i by A36,A35,PARTFUN1:def 6;
then
A39: mid(f,1,k).i = f/.i by A36,A35,FINSEQ_4:70;
i in NAT & 1 <= i by A37,FINSEQ_1:1;
then i in Seg (k+1) by A38;
then
A40: i in dom (f|(k+1)) by A33,FINSEQ_1:def 3;
then (f|(k+1)).i = (f|(k+1))/.i by PARTFUN1:def 6;
hence thesis by A26,A39,A40,FINSEQ_4:70;
end;
A41: k+1 >= 1 by NAT_1:14;
then
A42: k+1 in Seg len f by A32;
then
A43: k+1 in dom f by FINSEQ_1:def 3;
A44: k+1 in dom F by A6,A42,FINSEQ_1:def 3;
k+1 in Seg (k+1) by A41;
then
A45: k+1 in dom (f|(k+1)) by A33,FINSEQ_1:def 3;
then (f|(k+1))/.(k+1) = f/.(k+1) by FINSEQ_4:70;
then mid(f,1,k+1).(k+1) = f/.(k+1) by A26,A45,PARTFUN1:def 6;
then mid(f,1,k+1).(k+1) = f.(k+1) by A43,PARTFUN1:def 6
.= L.(F.(k+1)) by A8,A43;
then
A46: mid(f,1,k+1).(k+1) = L.(F/.(k+1)) by A44,PARTFUN1:def 6;
mid(f,1,k+1) = f|(k+1) by FINSEQ_6:116,NAT_1:14;
then
len <* mid(f,1,k+1).(k+1) *> = 1 & len mid(f,1,k+1) = k+1 by A32,
FINSEQ_1:40,59;
then
dom mid(f,1,k+1) = Seg (len mid(f,1,k) + len <* mid(f,1,k+ 1).(k+
1) *>) by A20,FINSEQ_1:def 3;
then mid(f,1,k+1)=mid(f,1,k)^<* mid(f,1,k+1).(k+1) *> by A34,A25,
FINSEQ_1:def 7;
then
A47: Sum(mid(f,1,k+1)) = Sum(mid(f,1,k)) + L.(F/.(k+1)) by A46,RVSUM_1:74;
A48: mid(L(#)F,1,k+1) = (L(#)F)|(k+1) by FINSEQ_6:116,NAT_1:14;
set w2 = F/.(k+1);
set w1 = Sum(mid(L(#)F,1,k));
set r2 = L.(F/.(k+1));
A49: (1/(r1+r2))*r1 = r1/(r1+r2) by XCMPLX_1:99;
A50: w2 in M & r2 > 0
proof
k+1 in Seg len f by A41,A32;
then k+1 in dom f by FINSEQ_1:def 3;
then
A51: f.(k+1) = L.(F.(k+1)) & f.(k+1) >= 0 by A8;
k+1 in Seg len F by A6,A41,A32;
then
A52: k+1 in dom F by FINSEQ_1:def 3;
then w2 = F.(k+1) by PARTFUN1:def 6;
then
A53: w2 in Carrier(L) by A4,A52,FUNCT_1:def 3;
Carrier(L) c= N by RLVECT_2:def 6;
hence w2 in M by A2,A53;
w2 in {v where v is Element of V : L.v <> 0} by A53,RLVECT_2:def 4;
then ex v being Element of V st v = w2 & L.v <> 0;
hence thesis by A52,A51,PARTFUN1:def 6;
end;
then r1+r2 > r1 by XREAL_1:29;
then
A54: (1/(r1+r2))*r1 < 1 by A31,A49,XREAL_1:189;
A55: r1+r2 > 0+(0 qua Nat) by A31,A50;
then 1/(r1+r2) > 0 by XREAL_1:139;
then
A56: 0 < (1/(r1+r2))*r1 by A31,XREAL_1:129;
k+1 <= len (L(#)F) by A6,A32,RLVECT_2:def 7;
then
A57: k+1 in dom (L(#)F) by A41,FINSEQ_3:25;
A58: k < len (L(#)F) by A6,A19,RLVECT_2:def 7;
then
A59: k+1 <= len (L(#)F) by NAT_1:13;
then
A60: len ((L(#)F)|(k+1)) = k+1 by FINSEQ_1:59;
A61: for i being Nat st i in dom mid(L(#)F,1,k) holds mid(L(#)F,1,k+1)
.i = mid(L(#)F,1,k).i
proof
let i be Nat;
A62: mid(L(#)F,1,k) = (L(#)F)|k by FINSEQ_6:116,NAT_1:14;
assume
A63: i in dom mid(L(#)F,1,k);
then
A64: i in Seg len((L(#)F)|k) by A62,FINSEQ_1:def 3;
len((L(#)F)|k) = k by A58,FINSEQ_1:59;
then i <= k by A64,FINSEQ_1:1;
then
A65: i <= k+1 by NAT_1:12;
((L(#)F)|k).i = ((L(#)F)|k)/.i by A63,A62,PARTFUN1:def 6;
then
A66: mid(L(#)F,1,k).i = (L(#)F)/.i by A63,A62,FINSEQ_4:70;
i in NAT & 1 <= i by A64,FINSEQ_1:1;
then i in Seg (k+1) by A65;
then
A67: i in dom ((L(#)F)|(k+1)) by A60,FINSEQ_1:def 3;
then ((L(#)F)|(k+1)).i = ((L(#)F)|(k+1))/.i by PARTFUN1:def 6;
hence thesis by A48,A66,A67,FINSEQ_4:70;
end;
k+1 in Seg (k+1) by A41;
then
A68: k+1 in dom ((L(#)F)|(k+1)) by A60,FINSEQ_1:def 3;
then ((L(#)F)|(k+1))/.(k+1) = (L(#)F)/.(k+1) by FINSEQ_4:70;
then mid((L(#)F),1,k+1).(k+1) = (L(#)F)/.(k+1) by A48,A68,
PARTFUN1:def 6;
then
A69: mid((L(#)F),1,k+1).(k+1) = (L(#)F).(k+1) by A57,PARTFUN1:def 6
.= L.(F/.(k+1)) * F/.(k+1) by A57,RLVECT_2:def 7;
mid(L(#)F,1,k) = (L(#)F)|k by FINSEQ_6:116,NAT_1:14;
then
A70: len mid(L(#)F,1,k) = k by A58,FINSEQ_1:59;
A71: for i being Nat st i in dom <* mid(L(#)F,1,k+1).(k+1) *> holds
mid(L(#)F,1,k+1).(len mid(L(#)F,1,k) + i) = <* mid(L(#)F,1,k+1).(k+1) *>.i
proof
let i be Nat;
assume i in dom <* mid(L(#)F,1,k+1).(k+1) *>;
then i in Seg 1 by FINSEQ_1:38;
then i = 1 by FINSEQ_1:2,TARSKI:def 1;
hence thesis by A70,FINSEQ_1:40;
end;
len <* mid(L(#)F,1,k+1).(k+1) *> = 1 & len mid(L(#)F,1,k+1) = k+1
by A59,A48,FINSEQ_1:40,59;
then
dom mid(L(#)F,1,k+1) = Seg (len mid(L(#)F,1,k) + len <* mid(L(#)F
,1,k+1).(k+1) *>) by A70,FINSEQ_1:def 3;
then mid(L(#)F,1,k+1) = mid(L(#)F,1,k)^<* mid(L(#)F,1,k+1).(k+1 ) *>
by A61,A71,FINSEQ_1:def 7;
then
A72: (1/Sum(mid(f,1,k+1)))*Sum(mid(L(#)F,1,k+1)) = (1/(r1+r2))*(w1+r2
*w2) by A47,A69,FVSUM_1:71
.= (1/(r1+r2))*(1 * w1 + r2 * w2)
by RLVECT_1:def 8
.= (1/(r1+r2))*((r1 * (1/r1)) * w1 + r2 * w2) by A31,XCMPLX_1:106
.= (1/(r1+r2))*(r1 * ((1/r1)*w1) + r2 * w2)
by RLVECT_1:def 7
.= (1/(r1+r2))*(r1 * ((1/r1)*w1)) +(1/(r1+r2))*(r2 * w2) by
RLVECT_1:def 5
.= (1/(r1+r2))*r1 * ((1/r1)*w1) +(1/(r1+r2))*(r2 * w2) by
RLVECT_1:def 7
.= (1/(r1+r2))*r1 * ((1/r1)*w1) +(1/(r1+r2))*r2 * w2 by
RLVECT_1:def 7;
1 - (1/(r1+r2))*r1 = (r1+r2)*(1/(r1+r2)) - (1/(r1+r2))*r1 by A55,
XCMPLX_1:106
.= (r1+r2-r1)*(1/(r1+r2));
hence thesis by A14,A50,A56,A54,A72,CONVEX1:def 2;
end;
end;
hence thesis;
end;
len F > 0 by A3,A4,A9,FINSEQ_4:62;
then
A73: len F >= 0 + 1 by NAT_1:13;
A74: P[1]
proof
mid(f,1,1) = f|1 by FINSEQ_6:116;
then
A75: len(mid(f,1,1)) = 1 by A6,A73,FINSEQ_1:59;
then 1 in dom mid(f,1,1) by FINSEQ_3:25;
then reconsider m = mid(f,1,1).1 as Element of REAL by PARTFUN1:4;
mid(f,1,1)= <* mid(f,1,1).1 *> by A75,FINSEQ_1:40;
then
A76: Sum(mid(f,1,1)) = m by FINSOP_1:11;
Carrier(L) c= N by RLVECT_2:def 6;
then
A77: Carrier(L) c= M by A2;
mid(L(#)F,1,1) = (L(#)F)|1 by FINSEQ_6:116;
then len(mid(L(#)F,1,1)) = 1 by A73,A11,FINSEQ_1:59;
then
A78: mid(L(#)F,1,1) = <* mid(L(#)F,1,1).1 *> by FINSEQ_1:40;
A79: 1 in Seg len (L(#)F) by A73,A11;
then
A80: 1 in dom F by A11,FINSEQ_1:def 3;
then
A81: F/.1 = F.1 by PARTFUN1:def 6;
A82: 1 in dom (L(#)F) by A79,FINSEQ_1:def 3;
A83: F.1 in rng F by A80,FUNCT_1:def 3;
then F.1 in {v where v is Element of V : L.v <> 0} by A4,RLVECT_2:def 4;
then
A84: ex v2 being Element of V st F.1 = v2 & L.v2 <> 0;
1 in dom f by A6,A11,A79,FINSEQ_1:def 3;
then f.1 = L.(F.1) by A8
.= L.(F/.1) by A80,PARTFUN1:def 6;
then
A85: Sum(mid(f,1,1)) = L.(F/.1) by A6,A73,A76,FINSEQ_6:123;
mid(L(#)F,1,1).1 = (L(#)F).1 by A73,A11,FINSEQ_6:123
.=L.(F/.1)*F/.1 by A82,RLVECT_2:def 7;
then
(1/Sum(mid(f,1,1)))*Sum(mid(L(#)F,1,1)) = (1/Sum(mid(f,1,1))) * (L.(F
/.1) * F/.1) by A78,RLVECT_1:44
.= ((1/Sum(mid(f,1,1))) * L.(F/.1)) * F/.1
by RLVECT_1:def 7
.= 1 * F/.1 by A81,A85,A84,XCMPLX_1:106
.= F/.1 by RLVECT_1:def 8;
hence thesis by A4,A81,A83,A77;
end;
for k being non zero Nat holds P[k] from NAT_1:sch 10(A74,A12);
then
A86: (1/Sum(mid(f,1,i)))*Sum(mid(L(#)F,1,i)) in M;
Sum(mid(f,1,len f)) = 1 by A6,A7,A73,FINSEQ_6:120;
then (1/Sum(mid(f,1,len f)))*Sum(mid(L(#)F,1,len(L(#)F))) = Sum(mid(L(#)F,1
,len(L(#)F))) by RLVECT_1:def 8
.= Sum(L (#) F) by A73,A10,FINSEQ_6:120;
hence thesis by A3,A4,A6,A86,A10,RLVECT_2:def 8;
end;
reconsider jj=1 as Element of REAL by XREAL_0:def 1;
Lm2: for V being RealLinearSpace, M being Subset of V st for N being Subset of
V, L being Linear_Combination of N st L is convex & N c= M holds Sum(L) in M
holds M is convex
proof
let V be RealLinearSpace;
let M be Subset of V;
assume
A1: for N being Subset of V, L being Linear_Combination of N st L is
convex & N c= M holds Sum(L) in M;
let u,v be VECTOR of V;
let rr be Real;
reconsider r=rr as Real;
assume that
A2: 0 < rr and
A3: rr < 1 and
A4: u in M & v in M;
set N = {u,v};
A5: N c= M by A4,ZFMISC_1:32;
reconsider N as Subset of V;
now
per cases;
suppose
A6: u <> v;
consider L being Linear_Combination of {u,v} such that
A7: L.u = r & L.v = (1-r) by A6,RLVECT_4:38;
reconsider L as Linear_Combination of N;
A8: L is convex
proof
A9: r-r < 1-r by A3,XREAL_1:9;
then v in {w where w is Element of V : L.w <> 0} by A7;
then
A10: v in Carrier L by RLVECT_2:def 4;
A11: for n being Element of NAT st n in dom <*r,1-r*> holds <*r,1-r*>.
n = L.(<*u,v*>.n) & <*r,1-r*>.n >= 0
proof
let n be Element of NAT;
assume n in dom <*r,1-r*>;
then n in Seg len <*r,1-r*> by FINSEQ_1:def 3;
then
A12: n in {1,2} by FINSEQ_1:2,44;
now
per cases by A12,TARSKI:def 2;
suppose
A13: n = 1;
then L.(<*u,v*>.n) = r by A7,FINSEQ_1:44;
hence thesis by A2,A13,FINSEQ_1:44;
end;
suppose
A14: n = 2;
then L.(<*u,v*>.n) = 1-r by A7,FINSEQ_1:44;
hence thesis by A9,A14,FINSEQ_1:44;
end;
end;
hence thesis;
end;
u in {w where w is Element of V : L.w <> 0} by A2,A7;
then u in Carrier L by RLVECT_2:def 4;
then
A15: Carrier L c= {u,v} & {u,v} c= Carrier L by A10,RLVECT_2:def 6
,ZFMISC_1:32;
take F=<*u,v*>;
A16: Sum(<*r,1-r*>) = r + (1-r) by RVSUM_1:77
.= 1;
thus F is one-to-one by A6,FINSEQ_3:94;
thus rng F = rng <*u*> \/ rng <*v*> by FINSEQ_1:31
.= {u} \/ rng <*v*> by FINSEQ_1:38
.= {u} \/ {v} by FINSEQ_1:38
.= {u,v} by ENUMSET1:1
.= Carrier L by A15,XBOOLE_0:def 10;
reconsider r as Element of REAL by XREAL_0:def 1;
reconsider jr=1-r as Element of REAL by XREAL_0:def 1;
take f=<*r,jr*>;
len <*r,1-r*> = 2 by FINSEQ_1:44
.= len <*u,v*> by FINSEQ_1:44;
hence len f = len F & Sum(f) = 1 & for n being Nat st n in dom f holds
f.n = L.(F.n) & f.n >= 0 by A16,A11;
end;
Sum(L)=r*u + (1-r)*v by A6,A7,RLVECT_2:33;
hence thesis by A1,A5,A8;
end;
suppose
A17: u = v;
consider L being Linear_Combination of {u} such that
A18: L.u = jj by RLVECT_4:37;
reconsider L as Linear_Combination of N by A17,ENUMSET1:29;
ex F being FinSequence of the carrier of V st F is one-to-one & rng
F = Carrier L & ex f being FinSequence of REAL st len f = len F & Sum(f) = 1 &
for n being Nat st n in dom f holds f.n = L.(F.n) & f.n >= 0
proof
take <*u*>;
A19: ex f being FinSequence of REAL st len f = len <*u*> & Sum(f) = 1
& for n being Nat st n in dom f holds f.n = L.(<*u*>.n) & f.n >= 0
proof
take ff;
A20: for n being Element of NAT st n in dom ff holds ff.n = L.(<*u*>
.n) & ff.n >= 0
proof
let n be Element of NAT;
assume n in dom ff;
then n in {1} by FINSEQ_1:2,38;
then
A21: n = 1 by TARSKI:def 1;
then ff.n = 1 by FINSEQ_1:40
.= L.(<*u*>.n) by A18,A21,FINSEQ_1:40;
hence thesis;
end;
len <*1*> = 1 by FINSEQ_1:39
.= len <*u*> by FINSEQ_1:39;
hence thesis by A20,FINSOP_1:11;
end;
u in {w where w is Element of V : L.w <> 0} by A18;
then
A22: u in Carrier L by RLVECT_2:def 4;
v in {w where w is Element of V : L.w <> 0} by A17,A18;
then v in Carrier L by RLVECT_2:def 4;
then Carrier L c= {u,v} & {u,v} c= Carrier L by A22,RLVECT_2:def 6
,ZFMISC_1:32;
then Carrier L = {u,v} by XBOOLE_0:def 10;
then Carrier L = {u} by A17,ENUMSET1:29;
hence thesis by A19,FINSEQ_1:38,FINSEQ_3:93;
end;
then L is convex;
then
A23: Sum(L) in M by A1,A5;
r*u + (1-r)*v = (r+(1-r))*u by A17,RLVECT_1:def 6
.= (0+1)*u;
hence thesis by A18,A23,RLVECT_2:32;
end;
end;
hence thesis;
end;
theorem
for V being RealLinearSpace, M being Subset of V holds (for N being
Subset of V, L being Linear_Combination of N st L is convex & N c= M holds Sum(
L) in M) iff M is convex by Lm1,Lm2;
definition
let V be RealLinearSpace, M be Subset of V;
defpred P[object] means $1 is Linear_Combination of M;
func LinComb(M) -> set means
for L being object holds L in it iff L is Linear_Combination of M;
existence
proof
consider A being set such that
A1: for x being object holds x in A iff x in Funcs(the carrier of V, REAL
) & P[x] from XBOOLE_0:sch 1;
take A;
let L be object;
thus L in A implies L is Linear_Combination of M by A1;
assume L is Linear_Combination of M;
hence thesis by A1;
end;
uniqueness
proof
thus for X1,X2 being set st
(for x being object holds x in X1 iff P[x]) & (
for x being object holds x in X2 iff P[x]) holds X1 = X2
from XBOOLE_0:sch 3;
end;
end;
registration
let V be RealLinearSpace;
cluster convex for Linear_Combination of V;
existence
proof
set u = the Element of V;
consider L being Linear_Combination of {u} such that
A1: L.u = jj by RLVECT_4:37;
reconsider L as Linear_Combination of V;
take L;
L is convex
proof
take <*u*>;
thus <*u*> is one-to-one by FINSEQ_3:93;
u in {w where w is Element of V : L.w <> 0} by A1;
then u in Carrier L by RLVECT_2:def 4;
then Carrier L c= {u} & {u} c= Carrier L by RLVECT_2:def 6,ZFMISC_1:31;
hence Carrier L = {u} by XBOOLE_0:def 10
.= rng<*u*> by FINSEQ_1:38;
take f = ff;
A2: for n being Element of NAT st n in dom f holds f.n = L.(<*u*>.n) & f.n >= 0
proof
let n be Element of NAT;
assume n in dom f;
then n in {1} by FINSEQ_1:2,38;
then
A3: n = 1 by TARSKI:def 1;
then f.n = L.u by A1,FINSEQ_1:40
.= L.(<*u*>.n) by A3,FINSEQ_1:40;
hence thesis;
end;
len <*1*> = 1 by FINSEQ_1:39
.= len <*u*> by FINSEQ_1:39;
hence thesis by A2,FINSOP_1:11;
end;
hence thesis;
end;
end;
definition
let V be RealLinearSpace;
mode Convex_Combination of V is convex Linear_Combination of V;
end;
registration
let V be RealLinearSpace, M be non empty Subset of V;
cluster convex for Linear_Combination of M;
existence
proof
consider u being object such that
A1: u in M by XBOOLE_0:def 1;
reconsider u as Element of V by A1;
consider L being Linear_Combination of {u} such that
A2: L.u = jj by RLVECT_4:37;
{u} c= M by A1,ZFMISC_1:31;
then reconsider L as Linear_Combination of M by RLVECT_2:21;
take L;
L is convex
proof
take <*u*>;
thus <*u*> is one-to-one by FINSEQ_3:93;
u in {w where w is Element of V : L.w <> 0} by A2;
then u in Carrier L by RLVECT_2:def 4;
then Carrier L c= {u} & {u} c= Carrier L by RLVECT_2:def 6,ZFMISC_1:31;
hence Carrier L = {u} by XBOOLE_0:def 10
.= rng <*u*> by FINSEQ_1:38;
take f=ff;
A3: for n being Element of NAT st n in dom f holds f.n = L.(<*u*>.n) & f.n >= 0
proof
let n be Element of NAT;
assume n in dom f;
then n in {1} by FINSEQ_1:2,38;
then
A4: n = 1 by TARSKI:def 1;
then f.n = L.u by A2,FINSEQ_1:40
.= L.(<*u*>.n) by A4,FINSEQ_1:40;
hence thesis;
end;
len <*1*> = 1 by FINSEQ_1:39
.= len <*u*> by FINSEQ_1:39;
hence thesis by A3,FINSOP_1:11;
end;
hence thesis;
end;
end;
definition
let V be RealLinearSpace, M be non empty Subset of V;
mode Convex_Combination of M is convex Linear_Combination of M;
end;
Lm3: for V being RealLinearSpace, W1,W2 being Subspace of V holds Up(W1+W2) =
Up(W1) + Up(W2)
proof
let V be RealLinearSpace;
let W1,W2 being Subspace of V;
A1: Up(W1+W2) = the carrier of W1+W2 by RUSUB_4:def 5
.= {v + u where u,v is VECTOR of V : v in W1 & u in W2} by RLSUB_2:def 1;
for x being object st x in Up(W1) + Up(W2) holds x in Up(W1+W2)
proof
let x be object;
assume x in Up(W1) + Up(W2);
then x in {u + v where u,v is Element of V: u in Up(W1) & v in Up(W2)} by
RUSUB_4:def 9;
then consider u,v being Element of V such that
A2: x = u + v and
A3: u in Up(W1) and
A4: v in Up(W2);
v in the carrier of W2 by A4,RUSUB_4:def 5;
then
A5: v in W2 by STRUCT_0:def 5;
u in the carrier of W1 by A3,RUSUB_4:def 5;
then u in W1 by STRUCT_0:def 5;
hence thesis by A1,A2,A5;
end;
then
A6: Up(W1) + Up(W2) c= Up(W1+W2);
for x being object st x in Up(W1+W2) holds x in Up(W1) + Up(W2)
proof
let x be object;
assume x in Up(W1+W2);
then consider u,v being VECTOR of V such that
A7: x = v + u and
A8: v in W1 and
A9: u in W2 by A1;
u in the carrier of W2 by A9,STRUCT_0:def 5;
then
A10: u in Up(W2) by RUSUB_4:def 5;
v in the carrier of W1 by A8,STRUCT_0:def 5;
then v in Up(W1) by RUSUB_4:def 5;
then
x in {u9 + v9 where u9,v9 is Element of V: u9 in Up(W1) & v9 in Up(W2
)} by A7,A10;
hence thesis by RUSUB_4:def 9;
end;
then Up(W1+W2) c= Up(W1) + Up(W2);
hence thesis by A6,XBOOLE_0:def 10;
end;
Lm4: for V being RealLinearSpace, W1,W2 being Subspace of V holds Up(W1 /\ W2)
= Up(W1) /\ Up(W2)
proof
let V be RealLinearSpace;
let W1,W2 be Subspace of V;
A1: Up(W1 /\ W2) = the carrier of W1 /\ W2 by RUSUB_4:def 5
.= (the carrier of W1) /\ (the carrier of W2) by RLSUB_2:def 2;
for x being object st x in Up(W1) /\ Up(W2) holds x in Up(W1 /\ W2)
proof
let x be object;
assume
A2: x in Up(W1) /\ Up(W2);
then x in Up(W2) by XBOOLE_0:def 4;
then
A3: x in the carrier of W2 by RUSUB_4:def 5;
x in Up(W1) by A2,XBOOLE_0:def 4;
then x in the carrier of W1 by RUSUB_4:def 5;
hence thesis by A1,A3,XBOOLE_0:def 4;
end;
then
A4: Up(W1) /\ Up(W2) c= Up(W1 /\ W2);
for x being object st x in Up(W1 /\ W2) holds x in Up(W1) /\ Up(W2)
proof
let x be object;
assume
A5: x in Up(W1 /\ W2);
then x in the carrier of W2 by A1,XBOOLE_0:def 4;
then
A6: x in Up(W2) by RUSUB_4:def 5;
x in the carrier of W1 by A1,A5,XBOOLE_0:def 4;
then x in Up(W1) by RUSUB_4:def 5;
hence thesis by A6,XBOOLE_0:def 4;
end;
then Up(W1 /\ W2) c= Up(W1) /\ Up(W2);
hence thesis by A4,XBOOLE_0:def 10;
end;
theorem
for V being RealLinearSpace, M be Subset of V holds Convex-Family M <> {};
Lm5: for V being RealLinearSpace, L1, L2 being Convex_Combination of V, a,b
being Real st a * b > 0 holds Carrier(a*L1 + b*L2) = Carrier(a * L1) \/ Carrier
(b * L2)
proof
let V be RealLinearSpace;
let L1, L2 be Convex_Combination of V;
let a,b be Real;
assume a * b > 0;
then
A1: not (a>=0 & b<=0 or a<=0 & b>=0);
then
A2: Carrier(L2) = Carrier(b * L2) by RLVECT_2:42;
A3: Carrier(L1) = Carrier(a * L1) by A1,RLVECT_2:42;
for x being object st x in Carrier(a * L1) \/ Carrier(b * L2) holds x in
Carrier(a*L1 + b*L2)
proof
let x be object;
assume
A4: x in Carrier(a * L1) \/ Carrier(b * L2);
now
per cases by A4,XBOOLE_0:def 3;
suppose
A5: x in Carrier(a * L1);
then x in {v where v is Element of V : (a * L1).v <> 0} by
RLVECT_2:def 4;
then consider v being Element of V such that
A6: v = x and
A7: (a * L1).v <> 0;
A8: L1.v > 0 by A3,A5,A6,CONVEX1:22;
v in Carrier(a*L1 + b*L2)
proof
now
per cases;
suppose
A9: v in Carrier(L2);
then
A10: L2.v > 0 by CONVEX1:22;
now
per cases by A1;
suppose
A11: a > 0 & b > 0;
then b*L2.v > 0 by A10,XREAL_1:129;
then (b*L2).v > 0 by RLVECT_2:def 11;
then
A12: (a*L1).v + (b*L2).v > (a*L1).v by XREAL_1:29;
a*L1.v > 0 by A8,A11,XREAL_1:129;
then (a*L1).v > 0 by RLVECT_2:def 11;
then (a*L1 + b*L2).v > 0 by A12,RLVECT_2:def 10;
hence thesis by RLVECT_2:19;
end;
suppose
A13: a < 0 & b < 0;
then a*L1.v < 0 by A3,A5,A6,CONVEX1:22,XREAL_1:132;
then (a*L1).v < 0 by RLVECT_2:def 11;
then
A14: (a*L1).v + (b*L2).v < (b*L2).v by XREAL_1:30;
b*L2.v < 0 by A9,A13,CONVEX1:22,XREAL_1:132;
then (b*L2).v < 0 by RLVECT_2:def 11;
then (a*L1 + b*L2).v < 0 by A14,RLVECT_2:def 10;
hence thesis by RLVECT_2:19;
end;
end;
hence thesis;
end;
suppose
not v in Carrier(L2);
then L2.v = 0 by RLVECT_2:19;
then b*L2.v = 0;
then (b*L2).v = 0 by RLVECT_2:def 11;
then (a*L1).v + (b*L2).v = (a*L1).v;
then (a*L1 + b*L2).v <> 0 by A7,RLVECT_2:def 10;
hence thesis by RLVECT_2:19;
end;
end;
hence thesis;
end;
hence thesis by A6;
end;
suppose
A15: x in Carrier(b * L2);
then x in {v where v is Element of V : (b * L2).v <> 0} by
RLVECT_2:def 4;
then consider v being Element of V such that
A16: v = x and
A17: (b * L2).v <> 0;
A18: L2.v > 0 by A2,A15,A16,CONVEX1:22;
v in Carrier(a*L1 + b*L2)
proof
now
per cases;
suppose
A19: v in Carrier(L1);
then
A20: L1.v > 0 by CONVEX1:22;
now
per cases by A1;
suppose
A21: a > 0 & b > 0;
then b*L2.v > 0 by A18,XREAL_1:129;
then (b*L2).v > 0 by RLVECT_2:def 11;
then
A22: (a*L1).v + (b*L2).v > (a*L1).v by XREAL_1:29;
a*L1.v > 0 by A20,A21,XREAL_1:129;
then (a*L1).v > 0 by RLVECT_2:def 11;
then (a*L1 + b*L2).v > 0 by A22,RLVECT_2:def 10;
hence thesis by RLVECT_2:19;
end;
suppose
A23: a < 0 & b < 0;
then a*L1.v < 0 by A19,CONVEX1:22,XREAL_1:132;
then (a*L1).v < 0 by RLVECT_2:def 11;
then
A24: (a*L1).v + (b*L2).v < (b*L2).v by XREAL_1:30;
b*L2.v < 0 by A2,A15,A16,A23,CONVEX1:22,XREAL_1:132;
then (b*L2).v < 0 by RLVECT_2:def 11;
then (a*L1 + b*L2).v < 0 by A24,RLVECT_2:def 10;
hence thesis by RLVECT_2:19;
end;
end;
hence thesis;
end;
suppose
not v in Carrier(L1);
then L1.v = 0 by RLVECT_2:19;
then a*L1.v = 0;
then (a*L1).v = 0 by RLVECT_2:def 11;
then (a*L1).v + (b*L2).v = (b*L2).v;
then (a*L1 + b*L2).v <> 0 by A17,RLVECT_2:def 10;
hence thesis by RLVECT_2:19;
end;
end;
hence thesis;
end;
hence thesis by A16;
end;
end;
hence thesis;
end;
then
A25: Carrier(a * L1) \/ Carrier(b * L2) c= Carrier(a*L1 + b*L2);
Carrier(a*L1 + b*L2) c= Carrier(a*L1) \/ Carrier(b*L2) by RLVECT_2:37;
hence thesis by A25,XBOOLE_0:def 10;
end;
Lm6: for F,G being Function st F,G are_fiberwise_equipotent for x1,x2 being
set st x1 in dom F & x2 in dom F & x1 <> x2 holds ex z1,z2 being set st z1 in
dom G & z2 in dom G & z1 <> z2 & F.x1 = G.z1 & F.x2 = G.z2
proof
let F,G be Function;
assume F,G are_fiberwise_equipotent;
then consider H being Function such that
A1: dom H = dom F and
A2: rng H = dom G and
A3: H is one-to-one and
A4: F = G*H by CLASSES1:77;
let x1,x2 be set;
assume that
A5: x1 in dom F and
A6: x2 in dom F and
A7: x1 <> x2;
A8: H.x1 in dom G & H.x2 in dom G by A5,A6,A1,A2,FUNCT_1:3;
A9: F.x2 = G.(H.x2) by A6,A4,FUNCT_1:12;
H.x1 <> H.x2 & F.x1 = G.(H.x1) by A5,A6,A7,A1,A3,A4,FUNCT_1:12,def 4;
hence thesis by A8,A9;
end;
Lm7: for V being RealLinearSpace, L being Linear_Combination of V, A being
Subset of V st A c= Carrier(L) holds ex L1 being Linear_Combination of V st
Carrier(L1) = A
proof
let V be RealLinearSpace;
let L be Linear_Combination of V;
let A be Subset of V;
consider F being Function such that
A1: L = F and
A2: dom F = the carrier of V and
A3: rng F c= REAL by FUNCT_2:def 2;
defpred P[object,object] means
($1 in A implies $2 = F.$1) & (not $1 in A implies
$2 = 0);
:: sklejenie funkcji ??? !!!
A4: for x being object st x in the carrier of V ex y being object st P[x,y]
proof
let x be object;
assume x in the carrier of V;
now
per cases;
suppose
x in A;
hence thesis;
end;
suppose
not x in A;
hence thesis;
end;
end;
hence thesis;
end;
consider L1 being Function such that
A5: dom L1 = the carrier of V &
for x being object st x in the carrier of V
holds P[x,L1.x] from CLASSES1:sch 1 (A4);
for y being object st y in rng L1 holds y in REAL
proof
let y be object;
assume y in rng L1;
then consider x being object such that
A6: x in dom L1 and
A7: y = L1.x by FUNCT_1:def 3;
reconsider x as Element of V by A5,A6;
now
per cases;
suppose
A8: x in A;
A9: F.x in rng F by A2,FUNCT_1:3;
y = F.x by A5,A7,A8;
hence thesis by A3,A9;
end;
suppose
not x in A;
then L1.x = In(0,REAL) by A5;
hence thesis by A7;
end;
end;
hence thesis;
end;
then rng L1 c= REAL;
then
A10: L1 is Element of Funcs(the carrier of V, REAL) by A5,FUNCT_2:def 2;
assume
A11: A c= Carrier(L);
then reconsider A as finite Subset of V by FINSET_1:1;
for v being Element of V st not v in A holds L1.v = 0 by A5;
then reconsider L1 as Linear_Combination of V by A10,RLVECT_2:def 3;
for v being object st v in Carrier(L1) holds v in A
proof
let v be object;
assume
A12: v in Carrier(L1);
then reconsider v as Element of V;
L1.v <> 0 by A12,RLVECT_2:19;
hence thesis by A5;
end;
then
A13: Carrier(L1) c= A;
take L1;
for v being object st v in A holds v in Carrier(L1)
proof
let v be object;
assume
A14: v in A;
then reconsider v as Element of V;
L1.v = F.v & L.v <> 0 by A11,A5,A14,RLVECT_2:19;
hence thesis by A1,RLVECT_2:19;
end;
then A c= Carrier(L1);
hence thesis by A13,XBOOLE_0:def 10;
end;
theorem Th8:
for V being RealLinearSpace, L1,L2 being Convex_Combination of V,
r being Real st 0 < r & r < 1 holds r*L1 + (1-r)*L2 is Convex_Combination of V
proof
let V be RealLinearSpace;
let L1,L2 be Convex_Combination of V;
let r be Real;
assume that
A1: 0 < r and
A2: r < 1;
A3: Carrier(r*L1) = Carrier(L1) by A1,RLVECT_2:42;
set Mid = Carrier(r*L1) /\ Carrier((1-r)*L2);
set L = r*L1 + (1-r)*L2;
consider F2 being FinSequence of the carrier of V such that
A4: F2 is one-to-one and
A5: rng F2 = Carrier(L2) and
A6: ex f being FinSequence of REAL st len f = len F2 & Sum(f) = 1 & for
n being Nat st n in dom f holds f.n = L2.(F2.n) & f.n >= 0 by CONVEX1:def 3;
set Btm = Carrier(L) \ Carrier(r*L1);
set Top = Carrier(L) \ Carrier((1-r)*L2);
consider F1 being FinSequence of the carrier of V such that
A7: F1 is one-to-one and
A8: rng F1 = Carrier(L1) and
A9: ex f being FinSequence of REAL st len f = len F1 & Sum(f) = 1 & for
n being Nat st n in dom f holds f.n = L1.(F1.n) & f.n >= 0 by CONVEX1:def 3;
consider Lt being Linear_Combination of V such that
A10: Carrier(Lt) = Top by Lm7,XBOOLE_1:36;
A11: r - r < 1 - r by A2,XREAL_1:9;
then
A12: Carrier((1-r)*L2) = Carrier(L2) by RLVECT_2:42;
A13: r*(1-r) > 0 by A1,A11,XREAL_1:129;
then
A14: Carrier(L) = Carrier(r*L1) \/ Carrier((1-r)*L2) by Lm5;
then consider Lm being Linear_Combination of V such that
A15: Carrier(Lm) = Mid by Lm7,XBOOLE_1:29;
consider Lb being Linear_Combination of V such that
A16: Carrier(Lb) = Btm by Lm7,XBOOLE_1:36;
consider Ft being FinSequence of the carrier of V such that
A17: Ft is one-to-one and
A18: rng Ft = Carrier(Lt) and
Sum(Lt) = Sum(Lt (#) Ft) by RLVECT_2:def 8;
consider Fb being FinSequence of the carrier of V such that
A19: Fb is one-to-one and
A20: rng Fb = Carrier(Lb) and
Sum(Lb) = Sum(Lb (#) Fb) by RLVECT_2:def 8;
consider Fm being FinSequence of the carrier of V such that
A21: Fm is one-to-one and
A22: rng Fm = Carrier(Lm) and
Sum(Lm) = Sum(Lm (#) Fm) by RLVECT_2:def 8;
A23: rng (Ft^Fm) = rng Ft \/ rng Fm by FINSEQ_1:31
.= ((Carrier(L1) \/ Carrier(L2)) \ Carrier(L2)) \/ (Carrier(L1) /\
Carrier(L2)) by A13,A3,A12,A10,A15,A18,A22,Lm5
.= ( Carrier(L1) \ Carrier(L2) ) \/ ( Carrier(L2) \ Carrier(L2) ) \/ (
Carrier(L1) /\ Carrier(L2)) by XBOOLE_1:42
.= ( Carrier(L1) \ Carrier(L2) ) \/ {} \/ (Carrier(L1) /\ Carrier(L2))
by XBOOLE_1:37
.= Carrier(L1) \ (Carrier(L2) \ Carrier(L2)) by XBOOLE_1:52
.= Carrier(L1) \ {} by XBOOLE_1:37
.= rng F1 by A8;
A24: rng Ft misses rng Fm by A10,A15,A18,A22,XBOOLE_1:17,85;
then
A25: Ft^Fm is one-to-one by A17,A21,FINSEQ_3:91;
set F = Ft^Fm^Fb;
consider f2 being FinSequence of REAL such that
A26: len f2 = len F2 and
A27: Sum(f2) = 1 and
A28: for n being Nat st n in dom f2 holds f2.n = L2.(F2.n) & f2.n >= 0 by A6;
deffunc F(set) = L1.(Ft.$1);
consider ft being FinSequence such that
A29: len ft = len Ft & for j being Nat st j in dom ft holds ft.j = F(j)
from FINSEQ_1:sch 2;
rng ft c= REAL
proof
let y be object;
consider L1f being Function such that
A30: L1 = L1f and
A31: dom L1f = the carrier of V and
A32: rng L1f c= REAL by FUNCT_2:def 2;
assume y in rng ft;
then consider x being object such that
A33: x in dom ft and
A34: ft.x = y by FUNCT_1:def 3;
reconsider x as Element of NAT by A33;
A35: ft.x = L1.(Ft.x) by A29,A33;
x in Seg len Ft by A29,A33,FINSEQ_1:def 3;
then x in dom Ft by FINSEQ_1:def 3;
then
A36: Ft.x in rng Ft by FUNCT_1:3;
rng Ft c= the carrier of V by FINSEQ_1:def 4;
then reconsider Ftx = Ft.x as Element of V by A36;
Ftx in dom L1f by A31;
then ft.x in rng L1f by A35,A30,FUNCT_1:3;
hence thesis by A34,A32;
end;
then reconsider ft as FinSequence of REAL by FINSEQ_1:def 4;
deffunc F(set) = L1.(Fm.$1);
consider fm1 being FinSequence such that
A37: len fm1 = len Fm & for j being Nat st j in dom fm1 holds fm1.j = F(
j) from FINSEQ_1:sch 2;
rng fm1 c= REAL
proof
let y be object;
consider L1f being Function such that
A38: L1 = L1f and
A39: dom L1f = the carrier of V and
A40: rng L1f c= REAL by FUNCT_2:def 2;
assume y in rng fm1;
then consider x being object such that
A41: x in dom fm1 and
A42: fm1.x = y by FUNCT_1:def 3;
reconsider x as Element of NAT by A41;
A43: fm1.x = L1.(Fm.x) by A37,A41;
x in Seg len Fm by A37,A41,FINSEQ_1:def 3;
then x in dom Fm by FINSEQ_1:def 3;
then
A44: Fm.x in rng Fm by FUNCT_1:3;
rng Fm c= the carrier of V by FINSEQ_1:def 4;
then reconsider Fmx = Fm.x as Element of V by A44;
Fmx in dom L1f by A39;
then fm1.x in rng L1f by A43,A38,FUNCT_1:3;
hence thesis by A42,A40;
end;
then reconsider fm1 as FinSequence of REAL by FINSEQ_1:def 4;
deffunc F(set) = L2.(Fm.$1);
consider fm2 being FinSequence such that
A45: len fm2 = len Fm & for j being Nat st j in dom fm2 holds fm2.j = F(
j) from FINSEQ_1:sch 2;
A46: for x being object st x in dom(ft^fm1) holds (ft^fm1).x = L1.((Ft^Fm).x)
proof
let x be object;
assume
A47: x in dom (ft^fm1);
then reconsider n = x as Element of NAT;
now
per cases by A47,FINSEQ_1:25;
suppose
A48: n in dom ft;
then n in Seg len Ft by A29,FINSEQ_1:def 3;
then
A49: n in dom Ft by FINSEQ_1:def 3;
ft.n = L1.(Ft.n) by A29,A48;
then (ft^fm1).n = L1.(Ft.n) by A48,FINSEQ_1:def 7;
hence thesis by A49,FINSEQ_1:def 7;
end;
suppose
ex m being Nat st m in dom fm1 & n = len ft + m;
then consider m being Element of NAT such that
A50: m in dom fm1 and
A51: n = len ft + m;
m in Seg len Fm by A37,A50,FINSEQ_1:def 3;
then
A52: m in dom Fm by FINSEQ_1:def 3;
(ft^fm1).n = fm1.m by A50,A51,FINSEQ_1:def 7
.= L1.(Fm.m) by A37,A50;
hence thesis by A29,A51,A52,FINSEQ_1:def 7;
end;
end;
hence thesis;
end;
for x being object holds x in dom (ft^fm1) iff x in dom(Ft^Fm) & (Ft^Fm).
x in dom L1
proof
let x be object;
A53: len (ft^fm1) = len ft + len fm1 by FINSEQ_1:22
.= len (Ft^Fm) by A29,A37,FINSEQ_1:22;
A54: dom(ft^fm1) = Seg len(ft^fm1) by FINSEQ_1:def 3
.= dom (Ft^Fm) by A53,FINSEQ_1:def 3;
x in dom (ft^fm1) implies (Ft^Fm).x in dom L1
proof
assume x in dom (ft^fm1);
then (Ft^Fm).x in rng (Ft^Fm) by A54,FUNCT_1:3;
then
A55: (Ft^Fm).x in Carrier(Lt) \/ Carrier(Lm) by A18,A22,FINSEQ_1:31;
dom L1 = the carrier of V by FUNCT_2:92;
hence thesis by A55;
end;
hence thesis by A54;
end;
then
A56: (ft^fm1) = L1*(Ft^Fm) by A46,FUNCT_1:10;
A57: dom L2 = the carrier of V by FUNCT_2:92;
A58: for x being object holds x in dom f2 iff x in dom F2 & F2.x in dom L2
proof
let x be object;
A59: now
assume x in dom f2;
then x in Seg len F2 by A26,FINSEQ_1:def 3;
hence x in dom F2 by FINSEQ_1:def 3;
then F2.x in rng F2 by FUNCT_1:3;
hence F2.x in dom L2 by A5,A57;
end;
now
assume that
A60: x in dom F2 and
F2.x in dom L2;
x in Seg len F2 by A60,FINSEQ_1:def 3;
hence x in dom f2 by A26,FINSEQ_1:def 3;
end;
hence thesis by A59;
end;
deffunc F(set) = L2.(Fb.$1);
consider fb being FinSequence such that
A61: len fb = len Fb & for j being Nat st j in dom fb holds fb.j = F(j)
from FINSEQ_1:sch 2;
rng fm2 c= REAL
proof
let y be object;
consider L2f being Function such that
A62: L2 = L2f and
A63: dom L2f = the carrier of V and
A64: rng L2f c= REAL by FUNCT_2:def 2;
assume y in rng fm2;
then consider x being object such that
A65: x in dom fm2 and
A66: fm2.x = y by FUNCT_1:def 3;
reconsider x as Element of NAT by A65;
A67: fm2.x = L2.(Fm.x) by A45,A65;
x in Seg len Fm by A45,A65,FINSEQ_1:def 3;
then x in dom Fm by FINSEQ_1:def 3;
then
A68: Fm.x in rng Fm by FUNCT_1:3;
rng Fm c= the carrier of V by FINSEQ_1:def 4;
then reconsider Fmx = Fm.x as Element of V by A68;
Fmx in dom L2f by A63;
then fm2.x in rng L2f by A67,A62,FUNCT_1:3;
hence thesis by A66,A64;
end;
then reconsider fm2 as FinSequence of REAL by FINSEQ_1:def 4;
A69: len (r*fm1) = len fm1 by RVSUM_1:117
.= len ((1-r)*fm2) by A37,A45,RVSUM_1:117;
rng fb c= REAL
proof
let y be object;
consider L2f being Function such that
A70: L2 = L2f and
A71: dom L2f = the carrier of V and
A72: rng L2f c= REAL by FUNCT_2:def 2;
assume y in rng fb;
then consider x being object such that
A73: x in dom fb and
A74: fb.x = y by FUNCT_1:def 3;
reconsider x as Element of NAT by A73;
A75: fb.x = L2.(Fb.x) by A61,A73;
x in Seg len Fb by A61,A73,FINSEQ_1:def 3;
then x in dom Fb by FINSEQ_1:def 3;
then
A76: Fb.x in rng Fb by FUNCT_1:3;
rng Fb c= the carrier of V by FINSEQ_1:def 4;
then reconsider Fbx = Fb.x as Element of V by A76;
Fbx in dom L2f by A71;
then fb.x in rng L2f by A75,A70,FUNCT_1:3;
hence thesis by A74,A72;
end;
then reconsider fb as FinSequence of REAL by FINSEQ_1:def 4;
set f = (r*ft)^(r*fm1 + (1-r)*fm2)^((1-r)*fb);
consider f1 being FinSequence of REAL such that
A77: len f1 = len F1 and
A78: Sum(f1) = 1 and
A79: for n being Nat st n in dom f1 holds f1.n = L1.(F1.n) & f1.n >= 0 by A9;
len f = len ((r*ft)^(r*fm1 + (1-r)*fm2)) + len((1-r)*fb) by FINSEQ_1:22
.= len(r*ft) + len(r*fm1 + (1-r)*fm2) + len((1-r)*fb) by FINSEQ_1:22
.= len ft + len(r*fm1 + (1-r)*fm2) + len((1-r)*fb) by RVSUM_1:117
.= len ft + len(r*fm1 + (1-r)*fm2) + len fb by RVSUM_1:117
.= len ft + len (r*fm1) + len fb by A69,INTEGRA5:2
.= len Ft + len Fm + len Fb by A29,A37,A61,RVSUM_1:117
.= len (Ft^Fm) + len Fb by FINSEQ_1:22;
then
A80: len f = len F by FINSEQ_1:22;
A81: dom L1 = the carrier of V by FUNCT_2:92;
A82: for x being object holds x in dom f1 iff x in dom F1 & F1.x in dom L1
proof
let x be object;
A83: now
assume x in dom f1;
then x in Seg len F1 by A77,FINSEQ_1:def 3;
hence x in dom F1 by FINSEQ_1:def 3;
then F1.x in rng F1 by FUNCT_1:3;
hence F1.x in dom L1 by A8,A81;
end;
now
assume that
A84: x in dom F1 and
F1.x in dom L1;
x in Seg len F1 by A84,FINSEQ_1:def 3;
hence x in dom f1 by A77,FINSEQ_1:def 3;
end;
hence thesis by A83;
end;
A85: rng (Ft^Fm) = Carrier(Lt) \/ Carrier(Lm) by A18,A22,FINSEQ_1:31;
for x being object st x in dom f1 holds f1.x = L1.(F1.x) by A79;
then
A86: f1 = L1*F1 by A82,FUNCT_1:10;
Ft^Fm is one-to-one by A17,A21,A24,FINSEQ_3:91;
then
A87: F1, Ft^Fm are_fiberwise_equipotent by A7,A23,RFINSEQ:26;
then dom F1 = dom (Ft^Fm) by RFINSEQ:3;
then
A88: Sum(f1) = Sum(ft^fm1) by A8,A87,A81,A86,A85,A56,CLASSES1:83,RFINSEQ:9;
A89: rng (Fm^Fb) = Carrier(Lm) \/ Carrier(Lb) by A22,A20,FINSEQ_1:31;
for x being object st x in dom f2 holds f2.x = L2.(F2.x) by A28;
then
A90: f2 = L2*F2 by A58,FUNCT_1:10;
A91: rng (Fm^Fb) = (Carrier(L) \ Carrier(r*L1)) \/ (Carrier(r*L1) /\
Carrier((1-r)*L2)) by A15,A16,A22,A20,FINSEQ_1:31
.= ((Carrier(L1) \/ Carrier(L2)) \ Carrier(L1)) \/ (Carrier(L1) /\
Carrier(L2)) by A13,A3,A12,Lm5
.= ( Carrier(L1) \ Carrier(L1) ) \/ ( Carrier(L2) \ Carrier(L1) ) \/ (
Carrier(L1) /\ Carrier(L2)) by XBOOLE_1:42
.= ( Carrier(L2) \ Carrier(L1) ) \/ {} \/ (Carrier(L1) /\ Carrier(L2))
by XBOOLE_1:37
.= Carrier(L2) \ (Carrier(L1) \ Carrier(L1)) by XBOOLE_1:52
.= Carrier(L2) \ {} by XBOOLE_1:37
.= rng F2 by A5;
for n being Element of NAT st n in dom f holds f.n = L.(F.n) & f.n >=0
proof
let n be Element of NAT;
assume
A92: n in dom f;
now
per cases by A92,FINSEQ_1:25;
suppose
A93: n in dom ((r*ft)^(r*fm1 + (1-r)*fm2));
then
A94: f.n = ((r*ft)^(r*fm1 + (1-r)*fm2)).n by FINSEQ_1:def 7;
now
per cases by A93,FINSEQ_1:25;
suppose
A95: n in dom(r*ft);
len((r*ft)^(r*fm1+(1-r)*fm2)) = len(r*ft) + len(r*fm1 + (1-r
)*fm2) by FINSEQ_1:22
.= len ft + len(r*fm1 + (1-r)*fm2) by RVSUM_1:117
.= len ft + len (r*fm1) by A69,INTEGRA5:2
.= len Ft + len Fm by A29,A37,RVSUM_1:117
.= len (Ft^Fm) by FINSEQ_1:22;
then n in Seg len(Ft^Fm) by A93,FINSEQ_1:def 3;
then n in dom (Ft^Fm) by FINSEQ_1:def 3;
then
A96: (Ft^Fm).n = F.n by FINSEQ_1:def 7;
A97: n in dom ft by A95,VALUED_1:def 5;
then n in Seg len Ft by A29,FINSEQ_1:def 3;
then
A98: n in dom Ft by FINSEQ_1:def 3;
then
A99: Ft.n in Carrier(Lt) by A18,FUNCT_1:3;
then reconsider Ftn = Ft.n as Element of V;
A100: f.n = (r*ft).n by A94,A95,FINSEQ_1:def 7
.= r*(ft.n) by RVSUM_1:44
.= r*(L1.(Ft.n)) by A29,A97;
not Ft.n in Carrier(L2) by A12,A10,A99,XBOOLE_0:def 5;
then L2.(Ftn) = 0 by RLVECT_2:19;
then (1-r)*L2.(Ftn) = 0;
then ((1-r)*L2).(Ftn) = 0 by RLVECT_2:def 11;
then f.n = (r*L1).(Ftn) + ((1-r)*L2).(Ftn) by A100,RLVECT_2:def 11
.= (r*L1 + (1-r)*L2).(Ft.n) by RLVECT_2:def 10;
hence f.n = L.(F.n) by A98,A96,FINSEQ_1:def 7;
A101: rng Ft c= rng (Ft^Fm) by FINSEQ_1:29;
Ft.n in rng Ft by A98,FUNCT_1:3;
then consider m9 being object such that
A102: m9 in dom F1 and
A103: F1.m9 = Ft.n by A23,A101,FUNCT_1:def 3;
reconsider m9 as Element of NAT by A102;
m9 in Seg len f1 by A77,A102,FINSEQ_1:def 3;
then m9 in dom f1 by FINSEQ_1:def 3;
then f1.m9 = L1.(F1.m9) & f1.m9 >= 0 by A79;
hence f.n >= 0 by A1,A100,A103;
end;
suppose
ex k being Nat st k in dom(r*fm1 + (1-r)*fm2) & n = len( r*ft) + k;
then consider m being Element of NAT such that
A104: m in dom(r*fm1 + (1-r)*fm2) and
A105: n=len(r*ft)+m;
len (r*fm1) = len fm1 by RVSUM_1:117
.= len ((1-r)*fm2) by A37,A45,RVSUM_1:117;
then
A106: len (r*fm1 + (1-r)*fm2) = len (r*fm1) by INTEGRA5:2
.= len fm1 by RVSUM_1:117;
then
A107: m in dom Fm by A37,A104,FINSEQ_3:29;
then
A108: Fm.m in rng Fm by FUNCT_1:3;
then reconsider Fmm = Fm.m as Element of V by A22;
A109: m in dom fm1 by A104,A106,FINSEQ_3:29;
A110: m in dom fm2 by A37,A45,A104,A106,FINSEQ_3:29;
A111: f.n = (r*fm1 + (1-r)*fm2).m by A94,A104,A105,FINSEQ_1:def 7
.= (r*fm1).m + ((1-r)*fm2).m by A104,VALUED_1:def 1
.= r*(fm1.m) + ((1-r)*fm2).m by RVSUM_1:44
.= r*(fm1.m) + (1-r)*(fm2.m) by RVSUM_1:44
.= r*(L1.(Fm.m)) + (1-r)*(fm2.m) by A37,A109
.= r*(L1.(Fm.m)) + (1-r)*(L2.(Fm.m)) by A45,A110;
len((r*ft)^(r*fm1+(1-r)*fm2)) = len(r*ft) + len(r*fm1 + (1-r
)*fm2) by FINSEQ_1:22
.= len ft + len(r*fm1 + (1-r)*fm2) by RVSUM_1:117
.= len ft + len (r*fm1) by A69,INTEGRA5:2
.= len Ft + len Fm by A29,A37,RVSUM_1:117
.= len (Ft^Fm) by FINSEQ_1:22;
then n in Seg len(Ft^Fm) by A93,FINSEQ_1:def 3;
then n in dom (Ft^Fm) by FINSEQ_1:def 3;
then
A112: (Ft^Fm).n = F.n by FINSEQ_1:def 7;
A113: len(r*ft) = len Ft by A29,RVSUM_1:117;
r*(L1.(Fmm)) = (r*L1).(Fm.m) & (1-r)*(L2.(Fmm)) = ((1-r)*L2)
.(Fm.m) by RLVECT_2:def 11;
then f.n = (r*L1 + (1-r)*L2).(Fm.m) by A111,RLVECT_2:def 10;
hence f.n = L.(F.n) by A105,A107,A112,A113,FINSEQ_1:def 7;
rng Fm c= rng (Ft^Fm) by FINSEQ_1:30;
then consider m9 being object such that
A114: m9 in dom F1 and
A115: F1.m9 = Fm.m by A23,A108,FUNCT_1:def 3;
reconsider m9 as Element of NAT by A114;
m9 in Seg len F1 by A114,FINSEQ_1:def 3;
then m9 in dom f1 by A77,FINSEQ_1:def 3;
then f1.m9 = L1.(F1.m9) & f1.m9 >= 0 by A79;
then
A116: r*L1.(Fm.m) >= 0 by A1,A115;
rng Fm c= rng (Fm^Fb) by FINSEQ_1:29;
then consider m9 being object such that
A117: m9 in dom F2 and
A118: F2.m9 = Fm.m by A91,A108,FUNCT_1:def 3;
reconsider m9 as Element of NAT by A117;
m9 in Seg len F2 by A117,FINSEQ_1:def 3;
then m9 in dom f2 by A26,FINSEQ_1:def 3;
then f2.m9 = L2.(F2.m9) & f2.m9 >= 0 by A28;
then (1-r)*L2.(Fm.m) >= 0 by A11,A118;
then r*(L1.(Fm.m)) + (1-r)*(L2.(Fm.m)) >= 0 + (0 qua Nat) by A116;
hence f.n >= 0 by A111;
end;
end;
hence thesis;
end;
suppose
ex m being Nat st m in dom((1-r)*fb) & n = len ((r*ft)^(r*
fm1 + (1-r)*fm2)) + m;
then consider m being Element of NAT such that
A119: m in dom((1-r)*fb) and
A120: n=len((r*ft)^(r*fm1+(1-r)*fm2))+m;
A121: m in dom fb by A119,VALUED_1:def 5;
then m in Seg len Fb by A61,FINSEQ_1:def 3;
then
A122: m in dom Fb by FINSEQ_1:def 3;
then
A123: Fb.m in rng Fb by FUNCT_1:3;
then reconsider Fbm = Fb.m as Element of V by A20;
A124: f.n = ((1-r)*fb).m by A119,A120,FINSEQ_1:def 7
.= (1-r)*(fb.m) by RVSUM_1:44
.= (1-r)*(L2.(Fb.m)) by A61,A121;
A125: len((r*ft)^(r*fm1+(1-r)*fm2)) = len(r*ft) + len(r*fm1 + (1-r)*
fm2) by FINSEQ_1:22
.= len ft + len(r*fm1 + (1-r)*fm2) by RVSUM_1:117
.= len ft + len (r*fm1) by A69,INTEGRA5:2
.= len Ft + len Fm by A29,A37,RVSUM_1:117
.= len (Ft^Fm) by FINSEQ_1:22;
not Fb.m in Carrier(L1) by A3,A16,A20,A123,XBOOLE_0:def 5;
then L1.(Fbm) = 0 by RLVECT_2:19;
then r*L1.(Fbm) = 0;
then (r*L1).(Fbm) = 0 by RLVECT_2:def 11;
then f.n = (r*L1).(Fbm) + ((1-r)*L2).(Fbm) by A124,RLVECT_2:def 11
.= (r*L1 + (1-r)*L2).(Fb.m) by RLVECT_2:def 10;
hence f.n = L.(F.n) by A120,A122,A125,FINSEQ_1:def 7;
rng Fb c= rng (Fm^Fb) by FINSEQ_1:30;
then consider m9 being object such that
A126: m9 in dom F2 and
A127: F2.m9 = Fb.m by A91,A123,FUNCT_1:def 3;
reconsider m9 as Element of NAT by A126;
m9 in Seg len F2 by A126,FINSEQ_1:def 3;
then m9 in dom f2 by A26,FINSEQ_1:def 3;
then f2.m9 = L2.(F2.m9) & f2.m9 >= 0 by A28;
hence f.n >= 0 by A11,A124,A127;
end;
end;
hence thesis;
end;
then
A128: for n being Nat st n in dom f holds f.n = L. (F.n) & f.n >= 0;
A129: rng Fb = Carrier(L) \ Carrier(L1) by A1,A16,A20,RLVECT_2:42;
then rng (Ft^Fm) misses rng Fb by A8,A23,XBOOLE_1:79;
then
A130: F is one-to-one by A19,A25,FINSEQ_3:91;
A131: for x being object st x in dom(fm2^fb) holds (fm2^fb).x = L2.((Fm^Fb).x)
proof
let x be object;
assume
A132: x in dom (fm2^fb);
then reconsider n = x as Element of NAT;
now
per cases by A132,FINSEQ_1:25;
suppose
A133: n in dom fm2;
then n in Seg len Fm by A45,FINSEQ_1:def 3;
then
A134: n in dom Fm by FINSEQ_1:def 3;
fm2.n = L2.(Fm.n) by A45,A133;
then (fm2^fb).n = L2.(Fm.n) by A133,FINSEQ_1:def 7;
hence thesis by A134,FINSEQ_1:def 7;
end;
suppose
ex m being Nat st m in dom fb & n = len fm2 + m;
then consider m being Element of NAT such that
A135: m in dom fb and
A136: n = len fm2 + m;
m in Seg len Fb by A61,A135,FINSEQ_1:def 3;
then
A137: m in dom Fb by FINSEQ_1:def 3;
(fm2^fb).n = fb.m by A135,A136,FINSEQ_1:def 7
.= L2.(Fb.m) by A61,A135;
hence thesis by A45,A136,A137,FINSEQ_1:def 7;
end;
end;
hence thesis;
end;
for x being object holds x in dom (fm2^fb) iff x in dom(Fm^Fb) & (Fm^Fb).
x in dom L2
proof
let x be object;
A138: len (fm2^fb) = len fm2 + len fb by FINSEQ_1:22
.= len (Fm^Fb) by A45,A61,FINSEQ_1:22;
A139: dom(fm2^fb) = Seg len(fm2^fb) by FINSEQ_1:def 3
.= dom (Fm^Fb) by A138,FINSEQ_1:def 3;
x in dom (fm2^fb) implies (Fm^Fb).x in dom L2
proof
assume x in dom (fm2^fb);
then (Fm^Fb).x in rng (Fm^Fb) by A139,FUNCT_1:3;
then
A140: (Fm^Fb).x in Carrier(Lm) \/ Carrier(Lb) by A22,A20,FINSEQ_1:31;
dom L2 = the carrier of V by FUNCT_2:92;
hence thesis by A140;
end;
hence thesis by A139;
end;
then
A141: (fm2^fb) = L2*(Fm^Fb) by A131,FUNCT_1:10;
rng Fm misses rng Fb by A15,A16,A22,A20,XBOOLE_1:17,85;
then Fm^Fb is one-to-one by A21,A19,FINSEQ_3:91;
then
A142: F2, Fm^Fb are_fiberwise_equipotent by A4,A91,RFINSEQ:26;
then dom F2 = dom (Fm^Fb) by RFINSEQ:3;
then
A143: Sum(f2) = Sum(fm2^fb) by A5,A142,A57,A90,A89,A141,CLASSES1:83,RFINSEQ:9;
A144: Sum(f) = Sum((r*ft)^(r*fm1 + (1-r)*fm2)) + Sum((1-r)*fb) by RVSUM_1:75
.= Sum(r*ft) + Sum(r*fm1 + (1-r)*fm2) + Sum((1-r)*fb) by RVSUM_1:75
.= r*Sum(ft) + Sum(r*fm1 + (1-r)*fm2) + Sum((1-r)*fb) by RVSUM_1:87
.= r*Sum(ft) + Sum(r*fm1 + (1-r)*fm2) + (1-r)*Sum(fb) by RVSUM_1:87
.= r*Sum(ft) + ( Sum(r*fm1) + Sum((1-r)*fm2) ) + (1-r)*Sum(fb) by A69,
INTEGRA5:2
.= r*Sum(ft)+( r*Sum(fm1) + Sum((1-r)*fm2) )+(1-r)*Sum(fb) by RVSUM_1:87
.= r*Sum(ft)+( r*Sum(fm1) + (1-r)*Sum(fm2) )+(1-r)*Sum(fb) by RVSUM_1:87
.= r*(Sum(ft)+Sum(fm1)) + (1-r)*(Sum(fm2)+Sum(fb))
.= r*(Sum(ft^fm1)) + (1-r)*(Sum(fm2)+Sum(fb)) by RVSUM_1:75
.= r*1 + (1-r)*1 by A78,A27,A88,A143,RVSUM_1:75
.= 0 + 1;
rng F = Carrier(L1) \/ (Carrier(L) \ Carrier(L1)) by A8,A23,A129,FINSEQ_1:31
.= Carrier(L1) \/ Carrier(L) by XBOOLE_1:39
.= Carrier(L) by A3,A14,XBOOLE_1:7,12;
hence thesis by A130,A144,A80,A128,CONVEX1:def 3;
end;
theorem
for V being RealLinearSpace, M being non empty Subset of V, L1,L2
being Convex_Combination of M, r being Real st 0 < r & r < 1 holds r*L1 + (1-r)
*L2 is Convex_Combination of M
proof
let V be RealLinearSpace;
let M be non empty Subset of V;
let L1,L2 be Convex_Combination of M;
let r be Real;
A1: r*L1 is Linear_Combination of M & (1-r)*L2 is Linear_Combination of M by
RLVECT_2:44;
assume 0 < r & r < 1;
hence thesis by A1,Th8,RLVECT_2:38;
end;
begin :: Miscellaneous
theorem
for V being RealLinearSpace, W1,W2 being Subspace of V holds Up(W1+W2)
= Up(W1) + Up(W2) by Lm3;
theorem
for V being RealLinearSpace, W1,W2 being Subspace of V holds Up(W1 /\
W2) = Up(W1) /\ Up(W2) by Lm4;
theorem
for V being RealLinearSpace, L1, L2 being Convex_Combination of V, a,b
being Real st a * b > 0 holds Carrier(a*L1 + b*L2) = Carrier(a * L1) \/ Carrier
(b * L2) by Lm5;
theorem
for F,G being Function st F,G are_fiberwise_equipotent for x1,x2 being
set st x1 in dom F & x2 in dom F & x1 <> x2 holds ex z1,z2 being set st z1 in
dom G & z2 in dom G & z1 <> z2 & F.x1 = G.z1 & F.x2 = G.z2 by Lm6;
theorem
for V being RealLinearSpace, L being Linear_Combination of V, A being
Subset of V st A c= Carrier(L) holds ex L1 being Linear_Combination of V st
Carrier(L1) = A by Lm7;