:: Topological Interpretation of Rough Sets
:: by Adam Grabowski
::
:: Received March 31, 2014
:: Copyright (c) 2014-2021 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 SUBSET_1, PRE_TOPC, SETFAM_1, STRUCT_0, TARSKI, ZFMISC_1,
XBOOLE_0, FUNCT_1, RELAT_1, RCOMP_1, XXREAL_0, CARD_1, QC_LANG1,
ORDERS_2, WAYBEL_9, TOPS_1, FINSUB_1, ROUGHS_4, BINOP_1, WAYBEL_1,
COHSP_1, ROUGHS_1, ROUGHS_2, ISOMICHI, FRECHET2, FRECHET, KURATO_1,
ARYTM_1, TDLAT_3;
notations TARSKI, XBOOLE_0, ZFMISC_1, SUBSET_1, ORDINAL1, NUMBERS, XXREAL_0,
SETFAM_1, RELAT_1, FUNCT_1, RELSET_1, PARTFUN1, FINSUB_1, XXREAL_2,
XXREAL_3, CARD_1, ENUMSET1, BINOP_1, FUNCT_2, FUNCT_3, XCMPLX_0, XREAL_0,
NAT_1, RCOMP_1, FUNCOP_1, FINSEQ_1, STRUCT_0, PRE_TOPC, ORDERS_2,
EQREL_1, TOPMETR, COHSP_1, TOPS_1, TDLAT_2, WAYBEL_9, ROUGHS_1, ROUGHS_2,
ISOMICHI, FRECHET, FRECHET2, KURATO_1, TDLAT_3;
constructors SETFAM_1, PARTFUN1, FUNCT_3, XXREAL_0, XREAL_0, NAT_1, MEMBERED,
XXREAL_1, XXREAL_2, XXREAL_3, FINSEQ_1, CONNSP_1, RELSET_1, NUMBERS,
BINOP_1, COHSP_1, TDLAT_2, FUNCOP_1, ORDERS_2, FINSUB_1, EQREL_1,
PCOMPS_1, PCOMPS_2, ROUGHS_1, ROUGHS_2, WAYBEL_9, TDLAT_3, TOPS_1,
ISOMICHI, FRECHET, FRECHET2, KURATO_1, TOPMETR, RCOMP_1, MEASURE6;
registrations XBOOLE_0, SUBSET_1, RELSET_1, FUNCT_2, STRUCT_0, XREAL_0,
FUNCT_1, ORDINAL1, TOPS_1, ROUGHS_1, ROUGHS_2, WAYBEL_9, PROB_1,
ISOMICHI, KURATO_1;
requirements NUMERALS, BOOLE, SUBSET;
begin :: Preliminaries
theorem :: ROUGHS_4:1
for T being set, F being Subset-Family of T holds
F = { B where B is Subset of T : B in F };
definition
let f be Function;
let A be set;
attr A is f-closed means
:: ROUGHS_4:def 1
A = f.A;
end;
definition let X be set, F be Subset-Family of X;
redefine attr F is cap-closed means
:: ROUGHS_4:def 2
for a,b being Subset of X st a in F & b in F holds a /\ b in F;
end;
definition let X be set;
let F be Subset-Family of X;
attr F is union-closed means
:: ROUGHS_4:def 3
for a being Subset-Family of X st a c= F holds union a in F;
end;
definition let X be set;
let F be Subset-Family of X;
attr F is topology-like means
:: ROUGHS_4:def 4
{} in F & X in F & F is union-closed cap-closed;
end;
registration let X be set;
cluster topology-like for Subset-Family of X;
end;
begin :: Maps
definition let X be set;
let f be Function of bool X, bool X;
attr f is extensive means
:: ROUGHS_4:def 5
for A being Subset of X holds A c= f.A;
attr f is intensive means
:: ROUGHS_4:def 6
for A being Subset of X holds f.A c= A;
attr f is idempotent means
:: ROUGHS_4:def 7
for A being Subset of X holds f.(f.A) = f.A;
attr f is c=-monotone means
:: ROUGHS_4:def 8
for A,B being Subset of X st A c= B holds f.A c= f.B;
attr f is \/-preserving means
:: ROUGHS_4:def 9
for A,B being Subset of X holds f.(A \/ B) = f.A \/ f.B;
attr f is /\-preserving means
:: ROUGHS_4:def 10
for A,B being Subset of X holds f.(A /\ B) = f.A /\ f.B;
end;
definition let X be set,
O be Function of bool X, bool X;
attr O is preclosure means
:: ROUGHS_4:def 11 :: Cech preclosure axioms
O is extensive \/-preserving empty-preserving;
attr O is closure means
:: ROUGHS_4:def 12 :: Kuratowski closure axioms
O is extensive idempotent \/-preserving empty-preserving;
attr O is preinterior means
:: ROUGHS_4:def 13 :: Kuratowski interior axioms
O is intensive /\-preserving universe-preserving;
attr O is interior means
:: ROUGHS_4:def 14 :: Kuratowski interior axioms
O is intensive idempotent /\-preserving universe-preserving;
end;
registration let X be set;
cluster \/-preserving -> c=-monotone for Function of bool X, bool X;
cluster /\-preserving -> c=-monotone for Function of bool X, bool X;
end;
:: preclosure implies monotonicity
:: Cl_Seq from FRECHET2 is important example of preclosure
registration let X be set;
cluster id bool X -> closure for Function of bool X, bool X;
cluster id bool X -> interior for Function of bool X, bool X;
end;
registration let X be set;
cluster closure interior for Function of bool X, bool X;
end;
registration let X be set;
cluster closure -> preclosure for Function of bool X, bool X;
end;
begin :: Structural Part
definition let T be 1-sorted;
mode map of T is Function of bool the carrier of T, bool the carrier of T;
end;
definition
struct (1-sorted) 1stOpStr
(# carrier -> set,
FirstOp -> Function of bool the carrier, bool the carrier #);
end;
definition
struct (1-sorted) 2ndOpStr
(# carrier -> set,
SecondOp -> Function of bool the carrier, bool the carrier #);
end;
definition
struct (1stOpStr, 2ndOpStr) TwoOpStruct
(# carrier -> set,
FirstOp, SecondOp ->
Function of bool the carrier, bool the carrier #);
end;
definition let X be 1stOpStr;
attr X is with_closure means
:: ROUGHS_4:def 15
the FirstOp of X is closure;
attr X is with_preclosure means
:: ROUGHS_4:def 16
the FirstOp of X is preclosure;
end;
registration let T be TopSpace;
cluster ClMap T -> closure;
cluster IntMap T -> interior;
end;
registration
cluster with_closure non empty for 1stOpStr;
end;
registration
cluster with_closure -> with_preclosure for 1stOpStr;
end;
definition let X be 1stOpStr;
let A be Subset of X;
attr A is op-closed means
:: ROUGHS_4:def 17
A = (the FirstOp of X).A;
end;
definition let X be 1stOpStr;
attr X is with_op-closed_subsets means
:: ROUGHS_4:def 18
ex A being Subset of X st A is op-closed;
end;
registration
cluster with_op-closed_subsets for 1stOpStr;
end;
registration let X be with_op-closed_subsets 1stOpStr;
cluster op-closed for Subset of X;
end;
definition let X be 2ndOpStr;
let A be Subset of X;
attr A is op-open means
:: ROUGHS_4:def 19
A = (the SecondOp of X).A;
end;
definition let X be 2ndOpStr;
attr X is with_op-open_subsets means
:: ROUGHS_4:def 20
ex A being Subset of X st A is op-open;
end;
registration
cluster with_op-open_subsets for 2ndOpStr;
end;
registration let X be with_op-open_subsets 2ndOpStr;
cluster op-open for Subset of X;
end;
definition let X be 2ndOpStr;
attr X is with_interior means
:: ROUGHS_4:def 21
the SecondOp of X is interior;
attr X is with_preinterior means
:: ROUGHS_4:def 22
the SecondOp of X is preinterior;
end;
registration
cluster with_closure with_interior for TwoOpStruct;
end;
begin :: Merging with Topologies
definition
struct (1stOpStr,TopStruct) 1TopStruct
(# carrier -> set,
FirstOp -> Function of bool the carrier, bool the carrier,
topology -> Subset-Family of the carrier #);
end;
definition
struct (2ndOpStr,TopStruct) 2TopStruct
(# carrier -> set,
SecondOp -> Function of bool the carrier, bool the carrier,
topology -> Subset-Family of the carrier #);
end;
registration
cluster non empty strict for 1TopStruct;
end;
registration
cluster non empty strict for 2TopStruct;
end;
definition let T be 1TopStruct;
attr T is with_properly_defined_topology means
:: ROUGHS_4:def 23
for x being object holds
x in the topology of T iff
ex S being Subset of T st S` = x & S is op-closed;
end;
definition let T be 2TopStruct;
attr T is with_properly_defined_Topology means
:: ROUGHS_4:def 24
for x being object holds
x in the topology of T iff
ex S being Subset of T st S = x & S is op-open;
end;
registration
cluster with_closure with_properly_defined_topology for 1TopStruct;
cluster with_interior with_properly_defined_Topology for 2TopStruct;
end;
theorem :: ROUGHS_4:2
for T being with_properly_defined_topology 1TopStruct,
A being Subset of T holds
A is op-closed iff A is closed;
registration
cluster with_preclosure -> TopSpace-like for
with_properly_defined_topology 1TopStruct;
end;
theorem :: ROUGHS_4:3
for T being with_properly_defined_Topology 2TopStruct,
A being Subset of T holds
A is op-open iff A is open;
registration
cluster with_preinterior -> TopSpace-like for
with_properly_defined_Topology 2TopStruct;
end;
theorem :: ROUGHS_4:4
for T being with_closure with_properly_defined_topology 1TopStruct,
A being Subset of T holds
(the FirstOp of T).A = Cl A;
begin :: Introducing Rough Sets
registration let R be Tolerance_Space;
cluster LAp R -> preinterior;
cluster UAp R -> preclosure;
end;
registration let R be Approximation_Space;
cluster LAp R -> interior;
cluster UAp R -> closure;
end;
definition let X be set,
f be Function of bool X, bool X;
func GenTop f -> Subset-Family of X means
:: ROUGHS_4:def 25
for x being object holds
x in it iff ex S being Subset of X st S = x & S is f-closed;
end;
theorem :: ROUGHS_4:5
for X being set,
f being Function of bool X, bool X st
f is preinterior holds
GenTop f is topology-like;
registration let C be set,
I be (Relation of C),
f be topology-like Subset-Family of C;
cluster TopRelStr (#C,I,f#) -> TopSpace-like;
end;
registration
cluster TopSpace-like with_equivalence non empty for TopRelStr;
end;
begin :: On Sequential Closure and Frechet Spaces
definition let T be non empty TopSpace;
func Cl_Seq T -> map of T means
:: ROUGHS_4:def 26
for A being Subset of T holds
it.A = Cl_Seq A;
end;
registration let T be non empty TopSpace;
cluster Cl_Seq T -> preclosure;
end;
registration
cluster Frechet for non empty TopSpace;
end;
registration let T be Frechet non empty TopSpace;
cluster Cl_Seq T -> closure;
end;
begin :: Connections between Closures and Approximations
definition let T be non empty TopRelStr;
attr T is Natural means
:: ROUGHS_4:def 27
for x being Subset of T holds
x in the topology of T iff x is (LAp T)-closed;
end;
definition let T be non empty TopRelStr;
attr T is naturally_generated means
:: ROUGHS_4:def 28
the topology of T = GenTop LAp T;
end;
theorem :: ROUGHS_4:6
for T being non empty TopRelStr st T is naturally_generated holds
for A being Subset of T holds
A is open iff LAp A = A;
theorem :: ROUGHS_4:7
for T being non empty TopRelStr,
R being non empty RelStr st
the RelStr of T = the RelStr of R holds
LAp T = LAp R;
theorem :: ROUGHS_4:8
for T being non empty TopRelStr,
R being non empty RelStr st
the RelStr of T = the RelStr of R holds
UAp T = UAp R;
registration
cluster Natural TopSpace-like with_equivalence for non empty TopRelStr;
end;
registration
cluster naturally_generated -> TopSpace-like for with_equivalence
non empty TopRelStr;
end;
registration
cluster naturally_generated TopSpace-like with_equivalence for
non empty TopRelStr;
end;
registration
let T be naturally_generated non empty with_equivalence TopRelStr;
let A be Subset of T;
cluster LAp A -> open;
end;
theorem :: ROUGHS_4:9
for T being naturally_generated non empty with_equivalence TopRelStr,
A being Subset of T holds
LAp A = Int A;
theorem :: ROUGHS_4:10
for T being naturally_generated non empty with_equivalence TopRelStr,
A being Subset of T holds
A is closed iff UAp A = A;
registration
let T be naturally_generated non empty with_equivalence TopRelStr,
A be Subset of T;
cluster UAp A -> closed;
end;
theorem :: ROUGHS_4:11
for T being naturally_generated non empty with_equivalence TopRelStr,
A being Subset of T holds
UAp A = Cl A;
theorem :: ROUGHS_4:12
for T being naturally_generated non empty with_equivalence TopRelStr,
A being Subset of T holds
BndAp A = Fr A;
registration
let T be with_equivalence naturally_generated non empty TopRelStr;
let A be Subset of T;
identify Int A with LAp A;
identify Cl A with UAp A;
identify LAp A with Int A;
identify UAp A with Cl A;
identify BndAp A with Fr A;
identify Fr A with BndAp A;
end;
begin :: Isomichi Results Reuse
theorem :: ROUGHS_4:13
for T being with_equivalence naturally_generated non empty TopRelStr,
A being Subset of T holds
A is 1st_class iff LAp UAp A c= UAp LAp A;
theorem :: ROUGHS_4:14
for T being with_equivalence naturally_generated non empty TopRelStr,
A being Subset of T holds
A is 1st_class iff UAp A c= LAp A;
theorem :: ROUGHS_4:15
for T being with_equivalence naturally_generated non empty TopRelStr,
A being Subset of T holds
A is 1st_class iff A is exact;
registration
let T be with_equivalence naturally_generated non empty TopRelStr;
cluster 1st_class -> exact for Subset of T;
cluster exact -> 1st_class for Subset of T;
end;
theorem :: ROUGHS_4:16
for T being with_equivalence naturally_generated non empty TopRelStr,
A being Subset of T holds
A is 2nd_class iff LAp A c< UAp A;
theorem :: ROUGHS_4:17
for T being with_equivalence naturally_generated non empty TopRelStr,
A being Subset of T holds
A is 2nd_class iff A is rough;
registration
let T be with_equivalence naturally_generated non empty TopRelStr;
cluster 2nd_class -> rough for Subset of T;
cluster rough -> 2nd_class for Subset of T;
end;
theorem :: ROUGHS_4:18
for T being with_equivalence naturally_generated non empty TopRelStr,
A being Subset of T holds
Cl Int A, Cl A are_c=-comparable;
theorem :: ROUGHS_4:19
for T being with_equivalence naturally_generated non empty TopRelStr,
A being Subset of T holds
not A is 3rd_class;
notation let T be TopSpace;
antonym T is without_3rd_class_subsets for
T is with_3rd_class_subsets;
end;
registration
cluster -> without_3rd_class_subsets for
with_equivalence naturally_generated non empty TopRelStr;
cluster without_3rd_class_subsets for TopSpace;
end;
registration
let T be TopSpace,
A be 1st_class Subset of T;
cluster Border A -> empty;
end;
registration
let T be with_equivalence naturally_generated non empty TopRelStr,
A be Subset of T;
cluster Cl A -> open;
cluster Int A -> closed;
end;
registration
cluster -> extremally_disconnected for
with_equivalence naturally_generated non empty TopRelStr;
end;
begin :: Reexamination of Kuratowski 14 Sets for Approximation Spaces
::$N Kuratowski's closure-complement problem
theorem :: ROUGHS_4:20
for T being with_equivalence naturally_generated non empty TopRelStr,
A being Subset of T holds
Kurat7Set A = { A, Cl A, Int A };
theorem :: ROUGHS_4:21
for T being with_equivalence naturally_generated non empty TopRelStr,
A being Subset of T holds
card Kurat7Set A <= 3;
theorem :: ROUGHS_4:22
for T being with_equivalence naturally_generated non empty TopRelStr,
A being Subset of T holds
Kurat14Set A = { A, UAp A, (UAp A)`, A`, (LAp A)`, LAp A };
theorem :: ROUGHS_4:23
for T being with_equivalence naturally_generated non empty TopRelStr,
A being Subset of T holds
card Kurat14Set A <= 6;