:: On the concept of the triangulation
:: by Beata Madras
::
:: Received October 28, 1995
:: Copyright (c) 1995-2016 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, SUBSET_1, XBOOLE_0, ORDERS_1, ORDERS_2, WELLORD1,
FINSET_1, XXREAL_0, TARSKI, STRUCT_0, FINSUB_1, SETFAM_1, RELAT_2,
RELAT_1, CARD_1, PRE_POLY, FINSEQ_1, PROB_1, PBOOLE, NAT_1, FUNCT_1,
ARYTM_3, FUNCOP_1, FUNCT_2, QC_LANG1, ORDINAL2, FINSEQ_2, PARTFUN1,
TRIANG_1;
notations TARSKI, XBOOLE_0, SUBSET_1, CARD_1, ORDINAL1, NUMBERS, RELAT_1,
RELAT_2, SETFAM_1, ORDERS_1, DOMAIN_1, XCMPLX_0, NAT_1, FUNCT_1,
PARTFUN1, FUNCT_2, FINSET_1, FINSEQ_1, FINSEQ_2, FINSUB_1, STRUCT_0,
WELLORD1, SEQM_3, PBOOLE, ORDERS_2, FINSEQOP, FUNCOP_1, XXREAL_0,
PRE_POLY;
constructors SETFAM_1, DOMAIN_1, FINSEQOP, PBOOLE, ORDERS_2, RELSET_1,
PRE_POLY, NUMBERS;
registrations XBOOLE_0, SETFAM_1, RELAT_1, FINSET_1, FINSUB_1, XXREAL_0,
NAT_1, FINSEQ_1, STRUCT_0, ORDERS_2, MEMBERED, VALUED_0, CARD_1,
RELSET_1, FUNCT_1, FUNCT_2, PRE_POLY, ORDINAL1, XCMPLX_0;
requirements REAL, NUMERALS, BOOLE, SUBSET, ARITHM;
definitions RELAT_2, TARSKI, FUNCT_1, XBOOLE_0, PBOOLE;
equalities WELLORD1, ORDERS_2, FINSEQ_2, SUBSET_1;
expansions RELAT_2, TARSKI, XBOOLE_0, PBOOLE;
theorems RELAT_1, ORDERS_2, RELAT_2, ZFMISC_1, TARSKI, SUBSET_1, ORDERS_1,
FINSUB_1, NAT_1, FUNCT_2, PBOOLE, FUNCT_1, FINSEQ_1, CARD_2, FINSEQ_4,
FINSEQ_2, FUNCOP_1, SEQM_3, SETFAM_1, XBOOLE_0, XBOOLE_1, XXREAL_0,
ORDINAL1, PARTFUN1, PRE_POLY, NUMBERS;
schemes PBOOLE, CLASSES1, MSSUBFAM, PRE_POLY;
begin
reserve A,x,y,z,u for set,
m,n for Element of NAT;
registration
let X be non empty set, R be Order of X;
cluster RelStr (#X,R#) -> non empty;
coherence;
end;
theorem
{}|_2 A = {};
theorem
for F being non empty Poset, A be Subset of F st A is finite & A <> {}
& for B,C being Element of F st B in A & C in A holds B <= C or C <= B ex m
being Element of F st m in A & for C being Element of F st C in A holds m <= C
proof
let F be non empty Poset;
defpred P[set] means $1 <> {} implies ex m being Element of F st m in $1 &
for C being Element of F st C in $1 holds m <= C;
let A be Subset of F such that
A1: A is finite and
A2: A <> {} and
A3: for B,C being Element of F st B in A & C in A holds B <= C or C <= B;
A4: now
let x be Element of F, B be Subset of F such that
A5: x in A and
A6: B c= A and
A7: P[B];
reconsider x9 = x as Element of F;
now
per cases;
suppose
A8: not ex y being Element of F st y in B & y <=x9;
assume B \/ {x} <> {};
take m = x9;
x in {x} by TARSKI:def 1;
hence m in B \/ {x} by XBOOLE_0:def 3;
let C be Element of F;
assume C in B \/ {x};
then
A9: C in B or C in {x} by XBOOLE_0:def 3;
then not C <=x9 or C=x by A8,TARSKI:def 1;
hence m <= C by A3,A5,A6,A9,TARSKI:def 1;
end;
suppose
A10: ex y being Element of F st y in B & y <=x9;
assume B \/ {x} <> {};
consider y being Element of F such that
A11: y in B and
A12: y <=x9 by A10;
consider m being Element of F such that
A13: m in B and
A14: for C being Element of F st C in B holds m <= C by A7,A11;
take m;
thus m in B \/ {x} by A13,XBOOLE_0:def 3;
let C be Element of F;
assume C in B \/ {x};
then
A15: C in B or C in {x} by XBOOLE_0:def 3;
m <= y by A11,A14;
then m <= x9 by A12,ORDERS_2:3;
hence m <= C by A14,A15,TARSKI:def 1;
end;
end;
hence P[B \/ {x}];
end;
A16: P[{}(the carrier of F)];
P[A] from PRE_POLY:sch 2(A1,A16,A4);
hence thesis by A2;
end;
registration
let P be non empty Poset, A be non empty finite Subset of P, x be Element of
P;
cluster InitSegm(A,x) -> finite;
coherence;
end;
begin :: Abstract Complexes
definition
let C be non empty Poset;
func symplexes(C) -> Subset of Fin the carrier of C equals
{A where A is
Element of Fin the carrier of C : the InternalRel of C linearly_orders A};
coherence
proof
set S = {A where A is Element of Fin the carrier of C : the InternalRel of
C linearly_orders A};
S c= Fin the carrier of C
proof
let x be object;
assume x in S;
then ex a be Element of Fin the carrier of C st x = a & the InternalRel
of C linearly_orders a;
hence thesis;
end;
hence thesis;
end;
end;
registration
let C be non empty Poset;
cluster symplexes(C) -> with_non-empty_element;
coherence
proof
set x = the Element of C;
reconsider a = {x} as Element of Fin the carrier of C by FINSUB_1:def 5;
A1: the InternalRel of C is_connected_in a
proof
let k,l be object;
assume that
A2: k in a and
A3: l in a and
A4: k <> l;
k = x by A2,TARSKI:def 1;
hence thesis by A3,A4,TARSKI:def 1;
end;
A5: field the InternalRel of C = the carrier of C by ORDERS_1:12;
then the InternalRel of C is_antisymmetric_in the carrier of C by
RELAT_2:def 12;
then
A6: the InternalRel of C is_antisymmetric_in a;
the InternalRel of C is_transitive_in the carrier of C by A5,RELAT_2:def 16
;
then
A7: the InternalRel of C is_transitive_in a;
the InternalRel of C is_reflexive_in the carrier of C by A5,RELAT_2:def 9;
then the InternalRel of C is_reflexive_in a;
then the InternalRel of C linearly_orders a by A6,A7,A1,ORDERS_1:def 9;
then a in {A where A is Element of Fin the carrier of C : the InternalRel
of C linearly_orders A};
hence thesis by SETFAM_1:def 10;
end;
end;
reserve C for non empty Poset;
theorem Th3:
for x be Element of C holds {x} in symplexes(C)
proof
let x be Element of C;
reconsider a = {x} as Element of Fin the carrier of C by FINSUB_1:def 5;
A1: the InternalRel of C is_connected_in a
proof
let k,l be object;
assume that
A2: k in a and
A3: l in a and
A4: k <> l;
k = x by A2,TARSKI:def 1;
hence thesis by A3,A4,TARSKI:def 1;
end;
A5: field the InternalRel of C = the carrier of C by ORDERS_1:12;
then the InternalRel of C is_antisymmetric_in the carrier of C by
RELAT_2:def 12;
then
A6: the InternalRel of C is_antisymmetric_in a;
the InternalRel of C is_transitive_in the carrier of C by A5,RELAT_2:def 16;
then
A7: the InternalRel of C is_transitive_in a;
the InternalRel of C is_reflexive_in the carrier of C by A5,RELAT_2:def 9;
then the InternalRel of C is_reflexive_in a;
then the InternalRel of C linearly_orders a by A6,A7,A1,ORDERS_1:def 9;
hence thesis;
end;
theorem
{} in symplexes(C)
proof
{} is Subset of C by SUBSET_1:1;
then reconsider a = {} as Element of Fin the carrier of C by FINSUB_1:def 5;
A1: the InternalRel of C is_antisymmetric_in a;
A2: the InternalRel of C is_connected_in a;
A3: the InternalRel of C is_transitive_in a;
the InternalRel of C is_reflexive_in a;
then the InternalRel of C linearly_orders a by A1,A3,A2,ORDERS_1:def 9;
hence thesis;
end;
theorem Th5:
for x, s be set st x c= s & s in symplexes(C) holds x in symplexes(C)
proof
let x, s be set;
assume that
A1: x c= s and
A2: s in symplexes(C);
consider s1 be Element of Fin the carrier of C such that
A3: s1 = s and
A4: the InternalRel of C linearly_orders s1 by A2;
s1 c= the carrier of C by FINSUB_1:def 5;
then x c= the carrier of C by A1,A3;
then reconsider x1 = x as Element of Fin the carrier of C by A1,A2,
FINSUB_1:def 5;
the InternalRel of C linearly_orders x by A1,A3,A4,ORDERS_1:38;
then
x1 in {A where A is Element of Fin the carrier of C : the InternalRel of
C linearly_orders A};
hence thesis;
end;
theorem Th6:
for C be non empty Poset, A being non empty Element of symplexes
(C) st card A = n holds dom(SgmX(the InternalRel of C, A)) = Seg n
proof
let C be non empty Poset, A be non empty Element of symplexes(C);
set f = SgmX(the InternalRel of C, A);
A in {A1 where A1 is Element of Fin the carrier of C : the InternalRel
of C linearly_orders A1};
then
A1: ex A1 being Element of Fin the carrier of C st A1 = A & the InternalRel
of C linearly_orders A1;
assume card A = n;
then len f = n by A1,PRE_POLY:11;
hence thesis by FINSEQ_1:def 3;
end;
registration
let C be non empty Poset;
cluster non empty for Element of symplexes(C);
existence
proof
set x = the Element of C;
{x} in symplexes(C) by Th3;
hence thesis;
end;
end;
begin :: Triangulations
definition
mode SetSequence is ManySortedSet of NAT;
end;
definition
let IT be SetSequence;
attr IT is lower_non-empty means
:Def2:
for n be Nat st IT.n is non empty
holds for m be Nat st m < n holds IT.m is non empty;
end;
registration
cluster lower_non-empty for SetSequence;
existence
proof
set f = NAT --> 1;
reconsider f as ManySortedSet of NAT;
take f;
for n be Nat st f.n is non empty holds for m be Nat st m < n holds f.m
is non empty
by FUNCOP_1:7,ORDINAL1:def 12;
hence thesis;
end;
end;
definition
let X be SetSequence;
func FuncsSeq X -> SetSequence means
:Def3:
for n be Nat holds it.n = Funcs( X.(n+1),X.n);
existence
proof
deffunc U(Element of NAT) = Funcs(X.($1+1),X.$1);
consider f be ManySortedSet of NAT such that
A1: for n being Element of NAT holds f.n = U(n) from PBOOLE:sch 5;
reconsider f as SetSequence;
take f;
let n be Nat;
n in NAT by ORDINAL1:def 12;
hence thesis by A1;
end;
uniqueness
proof
let a,b be SetSequence;
assume that
A2: for n be Nat holds a.n = Funcs(X.(n+1),X.n) and
A3: for n be Nat holds b.n = Funcs(X.(n+1),X.n);
let n be Element of NAT;
a.n = Funcs(X.(n+1),X.n) by A2;
hence a.n c= b.n by A3;
a.n = Funcs(X.(n+1),X.n) by A2;
hence b.n c= a.n by A3;
end;
end;
registration
let X be lower_non-empty SetSequence;
let n be Nat;
cluster (FuncsSeq X).n -> non empty;
coherence
proof
n < n + 1 by NAT_1:13;
then
A1: X.(n+1) = {} or X.n <> {} by Def2;
(FuncsSeq X).n = Funcs(X.(n+1),X.n) by Def3;
hence thesis by A1,FUNCT_2:8;
end;
end;
definition
let n be Nat;
let f be Element of Funcs(Seg n,Seg(n+1));
func @ f -> FinSequence of REAL equals
f;
coherence
proof
consider x be Function such that
A1: x = f and
dom x = Seg n and
rng x c= Seg(n+1) by FUNCT_2:def 2;
reconsider x as FinSequence of Seg(n+1) by A1,FINSEQ_2:25;
Seg(n+1) c= REAL by NUMBERS:19;
then x is FinSequence of REAL by FINSEQ_2:24;
hence thesis by A1;
end;
end;
definition
func NatEmbSeq -> SetSequence means
:Def5:
for n be Nat holds it.n = {f
where f is Element of Funcs(Seg n,Seg(n+1)) : @ f is increasing};
existence
proof
deffunc U(Element of NAT) = {f where f is Element of Funcs(Seg $1,Seg($1+1
)) : @ f is increasing};
consider F be ManySortedSet of NAT such that
A1: for n being Element of NAT holds F.n = U(n) from PBOOLE:sch 5;
reconsider F as SetSequence;
take F;
let n be Nat;
n in NAT by ORDINAL1:def 12;
hence thesis by A1;
end;
uniqueness
proof
let a,b be SetSequence;
assume that
A2: for n be Nat holds a.n = {f where f is Element of Funcs(Seg n,Seg(
n+1)) : @ f is increasing} and
A3: for n be Nat holds b.n = {f where f is Element of Funcs(Seg n,Seg(
n+ 1)) : @ f is increasing};
let n be Element of NAT;
a.n = {f where f is Element of Funcs(Seg n,Seg(n+1)) : @ f is
increasing } by A2;
hence a.n c= b.n by A3;
a.n = {f where f is Element of Funcs(Seg n,Seg(n+1)) : @ f is
increasing} by A2;
hence b.n c= a.n by A3;
end;
end;
registration
let n be Nat;
cluster NatEmbSeq.n -> non empty;
coherence
proof
n <= n + 1 by NAT_1:11;
then
A1: Seg n c= Seg(n+1) by FINSEQ_1:5;
A2: rng id Seg n = Seg n;
dom id Seg n = Seg n;
then reconsider n1 = (idseq n) as Element of Funcs(Seg n,Seg(n+1)) by A1,A2
,FUNCT_2:def 2;
@ n1 is increasing;
then n1 in {f where f is Element of Funcs(Seg n,Seg(n+1)) : @ f is
increasing};
hence thesis by Def5;
end;
end;
registration
let n be Nat;
cluster -> Function-like Relation-like for Element of NatEmbSeq.n;
coherence
proof
reconsider n9 = n as Element of NAT by ORDINAL1:def 12;
let x be Element of NatEmbSeq.n;
A1: x in NatEmbSeq.n9;
NatEmbSeq.n = {f where f is Element of Funcs(Seg n,Seg(n+1)) : @ f is
increasing} by Def5;
then ex f being Element of Funcs(Seg n,Seg(n+1)) st x = f & @ f is
increasing by A1;
hence thesis;
end;
end;
definition
let X be SetSequence;
mode triangulation of X is ManySortedFunction of NatEmbSeq, FuncsSeq(X);
end;
definition
struct TriangStr (# SkeletonSeq -> SetSequence, FacesAssign ->
ManySortedFunction of NatEmbSeq, FuncsSeq(the SkeletonSeq) #);
end;
definition
let T be TriangStr;
attr T is lower_non-empty means
:Def6:
the SkeletonSeq of T is lower_non-empty;
end;
registration
cluster lower_non-empty strict for TriangStr;
existence
proof
set Sk = NAT --> {};
reconsider Sk as ManySortedSet of NAT;
set A = the ManySortedFunction of NatEmbSeq, FuncsSeq(Sk);
take TriangStr (# Sk,A #);
for n be Nat st Sk.n is non empty holds for m be Nat st m < n holds Sk
.m is non empty
by FUNCOP_1:7,ORDINAL1:def 12;
then Sk is lower_non-empty;
hence thesis;
end;
end;
registration
let T be lower_non-empty TriangStr;
cluster the SkeletonSeq of T -> lower_non-empty;
coherence by Def6;
end;
registration
let S be lower_non-empty SetSequence, F be ManySortedFunction of NatEmbSeq,
FuncsSeq S;
cluster TriangStr (#S,F#) -> lower_non-empty;
coherence;
end;
begin :: Relationship between Abstract Complexes and Triangulations
definition
let T be TriangStr;
let n be Nat;
mode Symplex of T,n is Element of (the SkeletonSeq of T).n;
end;
definition
let n be Nat;
mode Face of n is Element of NatEmbSeq.n;
end;
definition
let T be lower_non-empty TriangStr, n be Nat, x be Symplex of T,n+1, f be
Face of n;
assume
A1: (the SkeletonSeq of T).(n+1) <> {};
func face (x,f) -> Symplex of T,n means
:Def7:
for F,G be Function st F = (
the FacesAssign of T).n & G = F.f holds it = G.x;
existence
proof
reconsider n9 = n as Element of NAT by ORDINAL1:def 12;
reconsider F = (the FacesAssign of T).n9 as Function of NatEmbSeq.n9, (
FuncsSeq(the SkeletonSeq of T)).n9 by PBOOLE:def 15;
F.f in (FuncsSeq(the SkeletonSeq of T)).n9 by FUNCT_2:5;
then
F.f in Funcs((the SkeletonSeq of T).(n+1),(the SkeletonSeq of T).n) by Def3
;
then consider G be Function such that
A2: G = F.f and
A3: dom G = (the SkeletonSeq of T).(n+1) and
A4: rng G c= (the SkeletonSeq of T).n by FUNCT_2:def 2;
G.x in rng G by A1,A3,FUNCT_1:def 3;
then reconsider S = G.x as Symplex of T,n by A4;
take S;
let F1,G1 be Function;
assume that
A5: F1 = (the FacesAssign of T).n and
A6: G1 = F1.f;
thus thesis by A2,A5,A6;
end;
uniqueness
proof
reconsider n9 = n as Element of NAT by ORDINAL1:def 12;
let S1,S2 be Symplex of T,n;
assume that
A7: for F,G be Function st F = (the FacesAssign of T).n & G = F.f
holds S1 = G.x and
A8: for F,G be Function st F = (the FacesAssign of T).n & G = F.f
holds S2 = G.x;
reconsider F = (the FacesAssign of T).n9 as Function of NatEmbSeq.n9, (
FuncsSeq(the SkeletonSeq of T)).n9 by PBOOLE:def 15;
F.f in (FuncsSeq(the SkeletonSeq of T)).n9 by FUNCT_2:5;
then F.f in Funcs((the SkeletonSeq of T).(n+1),(the SkeletonSeq of T).n)
by Def3;
then consider G be Function such that
A9: G = F.f and
dom G = (the SkeletonSeq of T).(n+1) and
rng G c= (the SkeletonSeq of T).n by FUNCT_2:def 2;
S1 = G.x by A7,A9;
hence thesis by A8,A9;
end;
end;
definition
let C be non empty Poset;
func Triang C -> lower_non-empty strict TriangStr means
(the SkeletonSeq of
it).0 = { {} } & (for n be Nat st n > 0 holds (the SkeletonSeq of it).n = {
SgmX(the InternalRel of C, A) where A is non empty Element of symplexes(C) :
card A = n }) & for n be Nat, f be Face of n, s be Element of (the SkeletonSeq
of it).(n+1) st s in (the SkeletonSeq of it).(n+1) for A be non empty Element
of symplexes(C) st SgmX(the InternalRel of C, A) = s holds face (s,f) = (SgmX(
the InternalRel of C, A)) * f;
existence
proof
deffunc U(Element of NAT) = IFEQ($1,0,{{}},{ SgmX(the InternalRel of C, s)
where s is non empty Element of symplexes(C) : card s = $1});
consider Sk being SetSequence such that
A1: for n holds Sk.n = U(n) from PBOOLE:sch 5;
A2: now
let n be Nat;
assume
A3: n <> 0;
n in NAT by ORDINAL1:def 12;
hence
Sk.n = IFEQ(n,0,{{}},{ SgmX(the InternalRel of C, s) where s is non
empty Element of symplexes(C) : card s = n}) by A1
.= {SgmX(the InternalRel of C, s) where s is non empty Element of
symplexes(C) : card s = n} by A3,FUNCOP_1:def 8;
end;
A4: Sk.0 = IFEQ(0,0,{{}},{ SgmX(the InternalRel of C, s) where s is non
empty Element of symplexes(C) : card s = 0}) by A1
.= { {} } by FUNCOP_1:def 8;
Sk is lower_non-empty
proof
defpred X[Nat] means Sk.$1 is non empty;
let n be Nat;
A5: for m st m < n & X[m+1] holds X[m]
proof
let m;
assume that
m < n and
A6: Sk.(m+1) is non empty;
consider g be object such that
A7: g in Sk.(m+1) by A6;
Sk.(m+1) = {SgmX(the InternalRel of C, s) where s is non empty
Element of symplexes(C) : card s = m+1} by A2;
then consider s be non empty Element of symplexes(C) such that
g = SgmX(the InternalRel of C, s) and
A8: card s = m+1 by A7;
set x = the Element of s;
reconsider sx = s \ {x} as finite set;
sx \/ {x} = s \/ {x} by XBOOLE_1:39;
then
A9: sx \/ {x} = s by XBOOLE_1:12;
not x in sx by ZFMISC_1:56;
then
A10: m + 1 = card sx + 1 by A8,A9,CARD_2:41;
per cases;
suppose
m = 0;
hence thesis by A4;
end;
suppose
A11: m <> 0;
then reconsider sx as non empty Element of symplexes(C) by A10,Th5,
XBOOLE_1:36;
SgmX(the InternalRel of C, sx) in {SgmX(the InternalRel of C,
s1) where s1 is non empty Element of symplexes(C) : card s1 = m} by A10;
hence thesis by A2,A11;
end;
end;
assume
A12: X[n];
A13: for m be Element of NAT st m <= n holds X[m] from PRE_POLY:sch 1(A12,A5);
let m be Nat;
assume
A14: m < n;
m in NAT by ORDINAL1:def 12;
hence thesis by A13,A14;
end;
then reconsider Sk as lower_non-empty SetSequence;
defpred X[object,object,object] means
ex n being Nat, y being Face of n st $2 = y &
$3 = n & for s be Element of Sk.(n+1) st s in Sk.(n+1) for A be non empty
Element of symplexes(C) st SgmX(the InternalRel of C, A) = s for g1 being
Function st g1 = $1 holds g1.s = (SgmX(the InternalRel of C, A)) * y;
A15: for i be object st i in NAT
for x be object st x in NatEmbSeq.i ex y
be object st y in (FuncsSeq Sk).i & X[y,x,i]
proof
let i be object;
assume i in NAT;
then reconsider n = i as Element of NAT;
let x be object;
assume
A16: x in NatEmbSeq.i;
then reconsider y = x as Face of n;
reconsider y1 = y as Function;
x in {f where f is Element of Funcs(Seg n,Seg(n+1)) : @ f is
increasing} by A16,Def5;
then
A17: ex f be Element of Funcs(Seg n,Seg(n+1)) st f = x & @ f is increasing;
then consider y2 be Function such that
A18: y2 = y1 and
A19: dom y2 = Seg n and
A20: rng y2 c= Seg(n+1) by FUNCT_2:def 2;
reconsider y2 as FinSequence by A19,FINSEQ_1:def 2;
A21: len y2 = n by A19,FINSEQ_1:def 3;
defpred X[object,object] means
ex f being Function st f = $1 & $2 = f * y1;
A22: for s being object st s in Sk.(n+1) ex u being object st X[s,u]
proof
let s be object;
assume s in Sk.(n+1);
then s in { SgmX(the InternalRel of C, s9) where s9 is non empty
Element of symplexes(C) : card s9 = n+1} by A2;
then consider A be non empty Element of symplexes(C) such that
A23: SgmX(the InternalRel of C, A) = s and
card A = n+1;
reconsider u = (SgmX(the InternalRel of C, A)) * y as set;
consider f be Function such that
A24: f = s by A23;
take u, f;
thus thesis by A23,A24;
end;
consider g being Function such that
A25: dom g = Sk.(n+1) and
A26: for s being object st s in Sk.(n+1) holds X[s,g.s] from CLASSES1:
sch 1(A22);
reconsider y2 as FinSequence of Seg(n+1) by A20,FINSEQ_1:def 4;
reconsider g9 = g as set;
take g9;
A27: y2 is one-to-one
proof
let a,b be object;
assume that
A28: a in dom y2 and
A29: b in dom y2 and
A30: y2.a = y2.b;
reconsider a,b as Element of NAT by A28,A29;
now
assume
A31: a <> b;
per cases by A31,XXREAL_0:1;
suppose
a < b;
hence contradiction by A17,A18,A28,A29,A30,SEQM_3:def 1;
end;
suppose
b < a;
hence contradiction by A17,A18,A28,A29,A30,SEQM_3:def 1;
end;
end;
hence thesis;
end;
rng g c= Sk.n
proof
reconsider F = symplexes(C) as with_non-empty_element Subset of Fin
the carrier of C;
let z be object;
assume z in rng g;
then consider a be object such that
A32: a in dom g and
A33: z = g.a by FUNCT_1:def 3;
consider f being Function such that
A34: f = a and
A35: g.a = f * y2 by A18,A25,A26,A32;
per cases;
suppose
A36: n = 0;
then Seg n = {};
then dom (f * y1) = {} by A18,A19,RELAT_1:25,XBOOLE_1:3;
then z = {} by A18,A33,A35;
hence thesis by A4,A36,TARSKI:def 1;
end;
suppose
A37: n <> 0;
f in { SgmX(the InternalRel of C, s1) where s1 is non empty
Element of symplexes(C) : card s1 = n+1} by A2,A25,A32,A34;
then consider s1 be non empty Element of symplexes(C) such that
A38: SgmX(the InternalRel of C, s1) = f and
A39: card s1 = n+1;
s1 in { A where A is Element of Fin the carrier of C : the
InternalRel of C linearly_orders A};
then
A40: ex s19 be Element of Fin the carrier of C st s19 = s1 & the
InternalRel of C linearly_orders s19;
then rng f = s1 by A38,PRE_POLY:def 2;
then reconsider f as FinSequence of s1 by A38,FINSEQ_1:def 4;
reconsider f as FinSequence of RelStr (#s1,(the InternalRel of C)|_2
s1#);
A41: f is one-to-one by A38,A40,PRE_POLY:10;
A42: dom f = Seg(n+1) by A38,A39,Th6;
A43: f is Function of dom f, s1 by FINSEQ_2:26;
then f is Function of Seg(n+1), the carrier of C by A42,FUNCT_2:7;
then reconsider
z1 = z as FinSequence of RelStr (#the carrier of C, the
InternalRel of C#) by A33,A35,FINSEQ_2:32;
reconsider f as Function of Seg(n+1), the carrier of C by A42,A43,
FUNCT_2:7;
A44: dom (f * y2) = Seg n by A19,A20,A42,RELAT_1:27;
rng(f * y2) c= the carrier of C by FINSEQ_1:def 4;
then reconsider
r = rng(f * y2) as Element of Fin the carrier of C by FINSUB_1:def 5;
rng(f * y2) c= s1 by RELAT_1:def 19;
then reconsider s9 = r as non empty Element of F by A37,A44,Th5,
RELAT_1:42;
for n1,m1 be Nat st n1 in dom z1 & m1 in dom z1 & n1 < m1 holds
z1/.n1 <> z1/.m1 & [z1/.n1,z1/.m1] in the InternalRel of C
proof
let n1, m1 be Nat;
assume that
A45: n1 in dom z1 and
A46: m1 in dom z1 and
A47: n1 < m1;
y2.m1 in Seg(n+1) by A19,A33,A35,A44,A46,FINSEQ_2:11;
then reconsider ym = y2.m1 as Element of NAT;
y2.n1 in Seg(n+1) by A19,A33,A35,A44,A45,FINSEQ_2:11;
then reconsider yn = y2.n1 as Element of NAT;
A48: yn < ym by A17,A18,A19,A33,A35,A44,A45,A46,A47,SEQM_3:def 1;
A49: ym in rng y2 by A19,A33,A35,A44,A46,FUNCT_1:def 3;
then reconsider
fm = f.ym as Element of RelStr (#s1,(the InternalRel of
C)|_2 s1#) by A20,A42,FINSEQ_2:11;
A50: fm = f/.ym by A20,A42,A49,PARTFUN1:def 6;
z1.m1 = fm by A33,A35,A46,FUNCT_1:12;
then reconsider
zm = z1.m1 as Element of RelStr (#s1,(the InternalRel
of C)|_2 s1#);
A51: zm = z1/.m1 by A46,PARTFUN1:def 6;
A52: z1.m1 = f.(y2.m1) by A33,A35,A46,FUNCT_1:12;
A53: z1.n1 = f.(y2.n1) by A33,A35,A45,FUNCT_1:12;
A54: yn in rng y2 by A19,A33,A35,A44,A45,FUNCT_1:def 3;
then reconsider
fn = f.yn as Element of RelStr (#s1,(the InternalRel of
C)|_2 s1#) by A20,A42,FINSEQ_2:11;
z1.n1 = fn by A33,A35,A45,FUNCT_1:12;
then reconsider
zn = z1.n1 as Element of RelStr (#s1,(the InternalRel
of C)|_2 s1#);
A55: zn = z1/.n1 by A45,PARTFUN1:def 6;
fn = f/.yn by A20,A42,A54,PARTFUN1:def 6;
hence thesis by A20,A38,A40,A42,A53,A52,A48,A54,A49,A50,A55,A51,
PRE_POLY:def 2;
end;
then
A56: z1 = SgmX(the InternalRel of C, s9) by A33,A35,PRE_POLY:9;
len(f * y2) = n by A20,A21,A42,FINSEQ_2:29;
then card s9 = n by A27,A41,FINSEQ_4:62;
then z in {SgmX(the InternalRel of C, s) where s is non empty
Element of symplexes(C) : card s = n} by A56;
hence thesis by A2,A37;
end;
end;
then g9 in Funcs(Sk.(n+1),Sk.n) by A25,FUNCT_2:def 2;
hence g9 in (FuncsSeq Sk).i by Def3;
reconsider y = x as Face of n by A16;
take n;
take y;
thus x = y & i = n;
let s be Element of Sk.(n+1);
assume s in Sk.(n+1);
then
A57: ex f being Function st f = s & g.s = f * y1 by A26;
let A be non empty Element of symplexes(C) such that
A58: SgmX(the InternalRel of C, A) = s;
let g1 be Function;
assume g1 = g9;
hence thesis by A58,A57;
end;
consider F being ManySortedFunction of NatEmbSeq, FuncsSeq Sk such that
A59: for i being object st i in NAT
ex f being Function of NatEmbSeq.i, (
FuncsSeq Sk).i st f = F.i &
for x being object st x in NatEmbSeq.i holds X[f.x,x,i]
from MSSUBFAM:sch 1 (A15);
take TriangStr(#Sk,F#);
thus (the SkeletonSeq of TriangStr(#Sk,F#)).0 = { {} } by A4;
thus for n be Nat st n > 0 holds (the SkeletonSeq of TriangStr(#Sk,F#)).n
= { SgmX(the InternalRel of C, s) where s is non empty Element of symplexes(C)
: card s = n} by A2;
let n be Nat;
n in NAT by ORDINAL1:def 12;
then consider f1 be Function of NatEmbSeq.n, (FuncsSeq Sk).n such that
A60: f1 = F.n and
A61: for x being object st x in NatEmbSeq.n
ex m being Nat, y being Face of m st x = y & n = m &
for s be Element of Sk.(m+1) st s in Sk.(m+1) for A be
non empty Element of symplexes(C) st SgmX(the InternalRel of C, A) = s
for g1
being Function st g1 = f1.x holds g1.s = (SgmX(the InternalRel of C, A)) * y
by A59;
let x be Face of n;
let s be Element of (the SkeletonSeq of TriangStr(#Sk,F#)).(n+1);
assume
A62: s in (the SkeletonSeq of TriangStr(#Sk,F#)).(n+1);
let A be non empty Element of symplexes(C);
assume
A63: SgmX(the InternalRel of C, A) = s;
A64: ex m being Nat, y being Face of m st x = y & n = m & for s be
Element of Sk.(m+1) st s in Sk.(m+1) for A be non empty Element of symplexes(C)
st SgmX(the InternalRel of C, A) = s for g1 being Function st g1 = f1.x holds
g1.s = (SgmX(the InternalRel of C, A)) * y by A61;
f1.x in (FuncsSeq Sk).n;
then f1.x in Funcs(Sk.(n+1),Sk.n) by Def3;
then consider G be Function such that
A65: f1.x = G and
dom G = Sk.(n+1) and
rng G c= Sk.n by FUNCT_2:def 2;
face (s,x) = G.s by A60,A62,A65,Def7;
hence thesis by A62,A63,A64,A65;
end;
uniqueness
proof
let T1,T2 be lower_non-empty strict TriangStr such that
A66: (the SkeletonSeq of T1).0 = { {} } and
A67: for n be Nat st n > 0 holds (the SkeletonSeq of T1).n = { SgmX(
the InternalRel of C, A) where A is non empty Element of symplexes(C) : card A
= n } and
A68: for n be Nat, f be Face of n, s be Element of (the SkeletonSeq
of T1).(n+1) st s in (the SkeletonSeq of T1).(n+1) for A be non empty Element
of symplexes(C) st SgmX(the InternalRel of C, A) = s holds face (s,f) = (SgmX(
the InternalRel of C, A)) * f and
A69: (the SkeletonSeq of T2).0 = { {} } and
A70: for n be Nat st n > 0 holds (the SkeletonSeq of T2).n = { SgmX(
the InternalRel of C, A) where A is non empty Element of symplexes(C) : card A
= n } and
A71: for n be Nat, f be Face of n, s be Element of (the SkeletonSeq
of T2).(n+1) st s in (the SkeletonSeq of T2).(n+1) for A be non empty Element
of symplexes(C) st SgmX(the InternalRel of C, A) = s holds face (s,f) = (SgmX(
the InternalRel of C, A)) * f;
A72: for x be object st x in NAT holds (the SkeletonSeq of T1).x = (the
SkeletonSeq of T2).x
proof
let x be object;
assume x in NAT;
then reconsider n = x as Element of NAT;
now
per cases;
suppose
n = 0;
hence (the SkeletonSeq of T1).n = (the SkeletonSeq of T2).n by A66
,A69;
end;
suppose
A73: n <> 0;
then (the SkeletonSeq of T1).n = {SgmX(the InternalRel of C, s)
where s is non empty Element of symplexes(C) : card s = n} by A67;
hence (the SkeletonSeq of T1).n = (the SkeletonSeq of T2).n by A70
,A73;
end;
end;
hence thesis;
end;
then
A74: the SkeletonSeq of T1 = the SkeletonSeq of T2;
now
let i be object;
assume i in NAT;
then reconsider n=i as Element of NAT;
reconsider F1n = (the FacesAssign of T1).n, F2n = (the FacesAssign of T2
).n as Function of NatEmbSeq.n, (FuncsSeq(the SkeletonSeq of T1)).n by A74,
PBOOLE:def 15;
A75: dom F2n = NatEmbSeq.n by FUNCT_2:def 1;
A76: now
let x be object;
assume x in NatEmbSeq.n;
then reconsider x1 = x as Face of n;
F1n.x1 in (FuncsSeq(the SkeletonSeq of T1)).n;
then F1n.x1 in Funcs((the SkeletonSeq of T1).(n+1),(the SkeletonSeq
of T1). n) by Def3;
then consider F1nx be Function such that
A77: F1nx = F1n.x1 and
A78: dom F1nx = (the SkeletonSeq of T1).(n+1) and
rng F1nx c= (the SkeletonSeq of T1).n by FUNCT_2:def 2;
F2n.x1 in (FuncsSeq(the SkeletonSeq of T1)).n;
then F2n.x1 in Funcs((the SkeletonSeq of T1).(n+1),(the SkeletonSeq
of T1). n) by Def3;
then consider F2nx be Function such that
A79: F2nx = F2n.x1 and
A80: dom F2nx = (the SkeletonSeq of T1).(n+1) and
rng F2nx c= (the SkeletonSeq of T1).n by FUNCT_2:def 2;
now
let y be object;
assume
A81: y in (the SkeletonSeq of T1).(n+1);
then reconsider y1 = y as Symplex of T1,(n+1);
A82: F1nx.y1 = face (y1,x1) by A77,A81,Def7;
reconsider y2 = y as Symplex of T2,(n+1) by A72,A81;
A83: F2nx.y2 = face (y2,x1) by A74,A79,A81,Def7;
y1 in {SgmX(the InternalRel of C, s) where s is non empty
Element of symplexes(C) : card s = n+1} by A67,A81;
then consider A be non empty Element of symplexes(C) such that
A84: SgmX(the InternalRel of C, A) = y1 and
card A = n+1;
face (y1,x1) = (SgmX(the InternalRel of C, A)) * x1 by A68,A81,A84;
hence F1nx.y = F2nx.y by A71,A74,A81,A82,A83,A84;
end;
hence F1n.x = F2n.x by A77,A78,A79,A80,FUNCT_1:2;
end;
dom F1n = NatEmbSeq.n by FUNCT_2:def 1;
hence (the FacesAssign of T1).i = (the FacesAssign of T2).i by A75,A76,
FUNCT_1:2;
end;
hence thesis by A74,PBOOLE:3;
end;
end;