:: Order Sorted Algebras
:: by Josef Urban
::
:: Received September 19, 2002
:: Copyright (c) 2002-2017 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 PBOOLE, FINSEQ_1, RELAT_1, TARSKI, XBOOLE_0, MSUALG_1, SUBSET_1,
STRUCT_0, EQREL_1, FUNCT_1, ORDERS_2, ORDERS_1, RELAT_2, NATTRA_1,
MARGREL1, XXREAL_0, SEQM_3, CARD_5, CARD_LAR, FUNCOP_1, CARD_3, SETFAM_1,
OSALG_1;
notations TARSKI, XBOOLE_0, SUBSET_1, RELAT_1, RELAT_2, FUNCT_1, RELSET_1,
ORDERS_1, FUNCT_2, EQREL_1, SETFAM_1, PARTFUN1, FINSEQ_1, FUNCOP_1,
FINSEQ_2, CARD_3, PBOOLE, ORDERS_2, STRUCT_0, MSUALG_1, ORDERS_3;
constructors EQREL_1, ORDERS_3, RELSET_1, MSAFREE;
registrations XBOOLE_0, SUBSET_1, FUNCT_1, RELSET_1, PARTFUN1, EQREL_1,
STRUCT_0, MSUALG_1, ORDERS_3, ORDINAL1, RELAT_1, PBOOLE, FINSEQ_1;
requirements BOOLE, SUBSET;
definitions TARSKI;
theorems FUNCT_1, PARTFUN1, FINSEQ_1, FUNCOP_1, PBOOLE, FUNCT_2, CARD_3,
FINSEQ_3, FINSEQ_2, RELAT_1, RELSET_1, EQREL_1, ZFMISC_1, ORDERS_3,
MSUALG_1, ORDERS_2, RELAT_2, GRFUNC_1, FUNCT_4, ORDERS_1, XTUPLE_0;
schemes FUNCT_1;
begin :: Preliminaries
:: TODO: constant ManySortedSet, constant OrderSortedSet,
:: constant -> order-sorted ManySortedSet of R
registration
let I be set, f be ManySortedSet of I, p be FinSequence of I;
cluster f * p -> FinSequence-like;
coherence
proof
rng p c= I;
then rng p c= dom f by PARTFUN1:def 2;
then dom(f*p) = dom p by RELAT_1:27
.= Seg len p by FINSEQ_1:def 3;
hence thesis by FINSEQ_1:def 2;
end;
end;
Lm1: for I being set, f being ManySortedSet of I, p being FinSequence of I
holds dom (f * p) = dom p & len (f * p) = len p
proof
let I be set, f be ManySortedSet of I, p be FinSequence of I;
reconsider q = f * p as FinSequence;
rng p c= I;
then rng p c= dom f by PARTFUN1:def 2;
then len q = len p by FINSEQ_2:29;
hence thesis by FINSEQ_3:29;
end;
definition
let S be non empty ManySortedSign;
mode SortSymbol of S is Element of S;
end;
definition
let S be non empty ManySortedSign;
mode OperSymbol of S is Element of the carrier' of S;
end;
:: Some structures
:: overloaded MSALGEBRA is modelled using an Equivalence_Relation
:: on carrier' ... partially hack enforced by previous articles,
:: partially can give more general treatment than the usual definition
definition
struct(ManySortedSign) OverloadedMSSign (# carrier -> set, carrier' -> set,
Overloading -> Equivalence_Relation of the carrier', Arity -> Function of the
carrier', the carrier*, ResultSort -> Function of the carrier', the carrier #);
end;
:: Order Sorted Signatures
definition
struct(ManySortedSign,RelStr) RelSortedSign (# carrier -> set, InternalRel
-> (Relation of the carrier), carrier' -> set, Arity -> Function of the
carrier', the carrier*, ResultSort -> Function of the carrier', the carrier #);
end;
definition
struct(OverloadedMSSign,RelSortedSign) OverloadedRSSign (# carrier -> set,
InternalRel -> (Relation of the carrier), carrier' -> set, Overloading ->
Equivalence_Relation of the carrier', Arity -> Function of the carrier', the
carrier*, ResultSort -> Function of the carrier', the carrier #);
end;
:: The inheritance for structures should be much improved, much of the
:: following is very bad hacking
reserve A,O for non empty set,
R for Order of A,
Ol for Equivalence_Relation of O,
f for Function of O,A*,
g for Function of O,A;
:: following should be possible, but isn't:
:: set RS0 = RelSortedSign(#A,R,O,f,g #);
:: inheritance of attributes for structures does not work!!! :
:: RelStr(#A,R#) is reflexive does not imply that for RelSortedSign(...)
theorem Th1:
OverloadedRSSign(#A,R,O,Ol,f,g #) is non empty non void reflexive
transitive antisymmetric
proof
set RS0 = OverloadedRSSign(#A,R,O,Ol,f,g #);
A1: field the InternalRel of RS0 = the carrier of RS0 by ORDERS_1:12;
then
A2: the InternalRel of RS0 is_antisymmetric_in the carrier of RS0 by
RELAT_2:def 12;
the InternalRel of RS0 is_reflexive_in the carrier of RS0 & the
InternalRel of RS0 is_transitive_in the carrier of RS0 by A1,RELAT_2:def 9
,def 16;
hence thesis by A2,ORDERS_2:def 2,def 3,def 4;
end;
registration
let A,R,O,Ol,f,g;
cluster OverloadedRSSign(#A,R,O,Ol,f,g #) -> strict non empty reflexive
transitive antisymmetric;
coherence by Th1;
end;
begin
:: order-sorted, ~=, discernable, op-discrete
reserve S for OverloadedRSSign;
:: should be stated for nonoverloaded, but the inheritance is bad
definition
let S;
attr S is order-sorted means
:Def1:
S is reflexive transitive antisymmetric;
end;
registration
cluster order-sorted -> reflexive transitive antisymmetric for
OverloadedRSSign;
coherence;
cluster strict non empty non void order-sorted for OverloadedRSSign;
existence
proof
set A = the non empty set,R = the Order of A,O = the non empty set,Ol =the
Equivalence_Relation of O,f = the Function of O,A*,g = the Function of O,A;
take OverloadedRSSign(#A,R,O,Ol,f,g #);
thus thesis;
end;
end;
registration
cluster non empty non void for OverloadedMSSign;
existence
proof
set X = the non empty non void OverloadedRSSign;
take X;
thus thesis;
end;
end;
definition
let S be non empty non void OverloadedMSSign;
let x,y be OperSymbol of S;
pred x ~= y means
:Def2:
[x,y] in the Overloading of S;
symmetry
proof
let x,y be OperSymbol of S;
field the Overloading of S = the carrier' of S by ORDERS_1:12;
then the Overloading of S is_symmetric_in the carrier' of S by
RELAT_2:def 11;
hence thesis by RELAT_2:def 3;
end;
reflexivity
proof
let x be OperSymbol of S;
field the Overloading of S = the carrier' of S by ORDERS_1:12;
then the Overloading of S is_reflexive_in the carrier' of S by
RELAT_2:def 9;
hence thesis by RELAT_2:def 1;
end;
end;
:: remove when transitivity implemented
theorem Th2:
for S being non empty non void OverloadedMSSign, o,o1,o2 being
OperSymbol of S holds o ~= o1 & o1 ~= o2 implies o ~= o2
proof
let S be non empty non void OverloadedMSSign;
let o,o1,o2 be OperSymbol of S;
field the Overloading of S = the carrier' of S by ORDERS_1:12;
then
A1: the Overloading of S is_transitive_in the carrier' of S by RELAT_2:def 16;
assume o ~= o1 & o1 ~= o2;
then [o,o1] in the Overloading of S & [o1,o2] in the Overloading of S;
then [o,o2] in the Overloading of S by A1,RELAT_2:def 8;
hence thesis;
end;
:: with previous definition, equivalent funcs with same rank could exist
definition
let S be non empty non void OverloadedMSSign;
attr S is discernable means
:Def3:
for x,y be OperSymbol of S st x ~= y &
the_arity_of x = the_arity_of y & the_result_sort_of x = the_result_sort_of y
holds x = y;
attr S is op-discrete means
the Overloading of S = id (the carrier' of S);
end;
theorem Th3:
for S being non empty non void OverloadedMSSign holds S is
op-discrete iff for x,y be OperSymbol of S st x ~= y holds x = y
proof
let S be non empty non void OverloadedMSSign;
set d = id the carrier' of S;
set opss = the carrier' of S;
set ol = the Overloading of S;
thus S is op-discrete implies for x,y be OperSymbol of S st x ~= y holds x =
y
by RELAT_1:def 10;
assume
A1: for x,y be OperSymbol of S st x ~= y holds x = y;
now
let x,y be object;
thus [x,y] in ol implies x in opss & x = y
proof
assume
A2: [x,y] in ol;
then ex x1,y1 being object
st [x,y] = [x1,y1] & x1 in opss & y1 in opss by
RELSET_1:2;
then reconsider x2 = x, y2 = y as OperSymbol of S by XTUPLE_0:1;
x2 ~= y2 by A2;
hence thesis by A1;
end;
assume x in opss & x = y;
hence [x,y] in ol by Def2;
end;
hence the Overloading of S = d by RELAT_1:def 10;
end;
theorem Th4:
for S being non empty non void OverloadedMSSign holds S is
op-discrete implies S is discernable
by Th3;
begin
:: OSSign of ManySortedSign, OrderSortedSign
reserve S0 for non empty non void ManySortedSign;
:: we require strictness here for simplicity, more interesting is whether
:: we could do a nonstrict version, keeping the remaining fields of S0;
definition
let S0;
func OSSign S0 -> strict non empty non void order-sorted OverloadedRSSign
means
:Def5:
the carrier of S0 = the carrier of it & id the carrier of S0 = the
InternalRel of it & the carrier' of S0 = the carrier' of it & id the carrier'
of S0 = the Overloading of it & the Arity of S0 = the Arity of it & the
ResultSort of S0 = the ResultSort of it;
existence
proof
set s = OverloadedRSSign(# the carrier of S0, id the carrier of S0, the
carrier' of S0, id the carrier' of S0, the Arity of S0, the ResultSort of S0 #)
;
reconsider s1 = s as strict non empty non void order-sorted
OverloadedRSSign by Def1;
take s1;
thus thesis;
end;
uniqueness;
end;
theorem Th5:
OSSign S0 is discrete op-discrete
proof
set s = OSSign S0;
set ol = the Overloading of s;
the carrier of S0 = the carrier of OSSign S0 & id the carrier of S0 =
the InternalRel of OSSign S0 by Def5;
hence OSSign S0 is discrete by ORDERS_3:def 1;
the Overloading of OSSign S0 = id the carrier' of S0 by Def5;
then for x,y be OperSymbol of s st x ~= y holds x = y by RELAT_1:def 10;
hence thesis by Th3;
end;
registration
cluster discrete op-discrete discernable for strict non empty non void
order-sorted OverloadedRSSign;
existence
proof
set S0 = the non empty non void ManySortedSign;
take s = OSSign S0;
thus s is discrete op-discrete by Th5;
hence thesis by Th4;
end;
end;
registration
cluster op-discrete -> discernable for non empty non void OverloadedRSSign;
coherence by Th4;
end;
::FIXME: the order of this and the previous clusters cannot be exchanged!!
registration
let S0;
cluster OSSign S0 -> discrete op-discrete;
coherence by Th5;
end;
definition
mode OrderSortedSign is discernable non empty non void order-sorted
OverloadedRSSign;
end;
:: monotonicity of OrderSortedSign
:: monotone overloaded signature means monotonicity for equivalent
:: operations
:: a stronger property of the Overloading should be stated ...
:: o1 ~= o2 implies len (the_arity_of o2) = len (the_arity_of o1)
:: ... probably not, unnecessary
reserve S for non empty Poset;
reserve s1,s2 for Element of S;
reserve w1,w2 for Element of (the carrier of S)*;
:: this is mostly done in YELLOW_1, but getting the constructors work
:: could be major effort; I don't care now
definition
let S;
let w1,w2 be Element of (the carrier of S)*;
pred w1 <= w2 means
len w1 = len w2 & for i being set st i in dom w1
for s1,s2 st s1 = w1.i & s2 = w2.i holds s1 <= s2;
reflexivity;
end;
theorem Th6:
for w1,w2 being Element of (the carrier of S)* holds w1 <= w2 &
w2 <= w1 implies w1 = w2
proof
let w1,w2 be Element of (the carrier of S)*;
assume that
A1: w1 <= w2 and
A2: w2 <= w1;
len w1 = len w2 by A1;
then
A3: dom w1 = dom w2 by FINSEQ_3:29;
for i being object st i in dom w1 holds w1.i = w2.i
proof
let i be object such that
A4: i in dom w1;
reconsider s3 = w1.i, s4 = w2.i as Element of S by A3,A4,PARTFUN1:4;
s3 <= s4 & s4 <= s3 by A1,A2,A3,A4;
hence thesis by ORDERS_2:2;
end;
hence thesis by A3,FUNCT_1:2;
end;
theorem Th7:
S is discrete & w1 <= w2 implies w1 = w2
proof
assume that
A1: S is discrete and
A2: w1 <= w2;
reconsider S1 = S as discrete non empty Poset by A1;
len w1 = len w2 by A2;
then
A3: dom w1 = dom w2 by FINSEQ_3:29;
for i being object st i in dom w1 holds w1.i = w2.i
proof
let i be object such that
A4: i in dom w1;
reconsider s3 = w1.i, s4 = w2.i as Element of S by A3,A4,PARTFUN1:4;
reconsider s5 = s3, s6 = s4 as Element of S1;
s3 <= s4 by A2,A4;
then s5 = s6 by ORDERS_3:1;
hence thesis;
end;
hence thesis by A3,FUNCT_1:2;
end;
reserve S for OrderSortedSign;
reserve o,o1,o2 for OperSymbol of S;
reserve w1 for Element of (the carrier of S)*;
theorem Th8:
S is discrete & o1 ~= o2 & (the_arity_of o1) <= (the_arity_of o2)
& the_result_sort_of o1 <= the_result_sort_of o2 implies o1 = o2
proof
assume
A1: S is discrete;
then reconsider S1 = S as discrete OrderSortedSign;
reconsider s1 = the_result_sort_of o1, s2 = the_result_sort_of o2 as
SortSymbol of S1;
assume that
A2: o1 ~= o2 and
A3: (the_arity_of o1) <= (the_arity_of o2) and
A4: the_result_sort_of o1 <= the_result_sort_of o2;
A5: s1 = s2 by A4,ORDERS_3:1;
(the_arity_of o1) = (the_arity_of o2) by A1,A3,Th7;
hence thesis by A2,A5,Def3;
end;
:: monotonicity of the signature
:: this doesnot extend to Overloading!
definition
let S;
let o;
attr o is monotone means
:Def7:
for o2 st o ~= o2 & (the_arity_of o) <= (
the_arity_of o2) holds the_result_sort_of o <= the_result_sort_of o2;
end;
definition
let S;
attr S is monotone means
:Def8:
for o being OperSymbol of S holds o is monotone;
end;
theorem Th9:
S is op-discrete implies S is monotone
proof
set ol = the Overloading of S;
assume S is op-discrete;
then
A1: ol = id the carrier' of S;
let o be OperSymbol of S;
let o2 be OperSymbol of S;
assume o ~= o2;
then [o,o2] in ol;
hence thesis by A1,RELAT_1:def 10;
end;
registration
cluster monotone for OrderSortedSign;
existence
proof
set S = the op-discrete OrderSortedSign;
take S;
thus thesis by Th9;
end;
end;
registration
let S be monotone OrderSortedSign;
cluster monotone for OperSymbol of S;
existence
proof
set o = the OperSymbol of S;
take o;
thus thesis by Def8;
end;
end;
registration
let S be monotone OrderSortedSign;
cluster -> monotone for OperSymbol of S;
coherence by Def8;
end;
registration
cluster op-discrete -> monotone for OrderSortedSign;
coherence by Th9;
end;
theorem :: constants not overloaded if monotone
S is monotone & the_arity_of o1 = {} & o1 ~= o2 & the_arity_of o2 = {}
implies o1=o2
proof
assume that
A1: S is monotone and
A2: the_arity_of o1 = {} & o1 ~= o2 & the_arity_of o2 = {};
the_result_sort_of o1 <= the_result_sort_of o2 & the_result_sort_of o2
<= the_result_sort_of o1 by A1,A2,Def7;
then the_result_sort_of o1 = the_result_sort_of o2 by ORDERS_2:2;
hence thesis by A2,Def3;
end;
:: least args,sort,rank,regularity for OperSymbol and
:: monotone OrderSortedSign
:: least bound for arguments
definition
let S,o,o1,w1;
pred o1 has_least_args_for o,w1 means
o ~= o1 & w1 <= the_arity_of
o1 & for o2 st o ~= o2 & w1 <= the_arity_of o2 holds the_arity_of o1 <=
the_arity_of o2;
pred o1 has_least_sort_for o,w1 means
o ~= o1 & w1 <= the_arity_of
o1 & for o2 st o ~= o2 & w1 <= the_arity_of o2 holds the_result_sort_of o1 <=
the_result_sort_of o2;
end;
definition
let S,o,o1,w1;
pred o1 has_least_rank_for o,w1 means
o1 has_least_args_for o,w1 & o1 has_least_sort_for o,w1;
end;
definition
let S,o;
attr o is regular means
:Def12:
o is monotone & for w1 st w1 <= the_arity_of
o ex o1 st o1 has_least_args_for o,w1;
end;
definition
let SM be monotone OrderSortedSign;
attr SM is regular means
:Def13:
for om being OperSymbol of SM holds om is regular;
end;
reserve SM for monotone OrderSortedSign,
o,o1,o2 for OperSymbol of SM,
w1 for Element of (the carrier of SM)*;
theorem Th11:
SM is regular iff for o,w1 st w1 <= the_arity_of o ex o1 st o1
has_least_rank_for o,w1
proof
hereby
assume
A1: SM is regular;
let o,w1;
assume
A2: w1 <= the_arity_of o;
o is regular by A1;
then consider o1 such that
A3: o1 has_least_args_for o,w1 by A2;
take o1;
o1 has_least_sort_for o,w1
proof
thus
A4: o ~= o1 & w1 <= the_arity_of o1 by A3;
let o2;
assume that
A5: o ~= o2 and
A6: w1 <= the_arity_of o2;
A7: o1 ~= o2 by A4,A5,Th2;
the_arity_of o1 <= the_arity_of o2 by A3,A5,A6;
hence thesis by A7,Def7;
end;
hence o1 has_least_rank_for o,w1 by A3;
end;
assume
A8: for o,w1 st w1 <= the_arity_of o ex o1 st o1 has_least_rank_for o, w1;
let o;
thus o is monotone;
let w1;
assume w1 <= the_arity_of o;
then consider o1 such that
A9: o1 has_least_rank_for o,w1 by A8;
take o1;
thus thesis by A9;
end;
theorem Th12:
for SM being monotone OrderSortedSign holds SM is op-discrete
implies SM is regular
proof
let SM be monotone OrderSortedSign;
assume
A1: SM is op-discrete;
let om be OperSymbol of SM;
thus om is monotone;
let wm1 be Element of (the carrier of SM)* such that
A2: wm1 <= the_arity_of om;
om has_least_args_for om,wm1
by A2,A1,Th3;
hence thesis;
end;
registration
cluster regular for monotone OrderSortedSign;
existence
proof
set SM = the op-discrete OrderSortedSign;
take SM;
thus thesis by Th12;
end;
end;
registration
cluster op-discrete -> regular for monotone OrderSortedSign;
coherence by Th12;
end;
registration
let SR be regular monotone OrderSortedSign;
cluster -> regular for OperSymbol of SR;
coherence by Def13;
end;
reserve SR for regular monotone OrderSortedSign,
o,o1,o3,o4 for OperSymbol of SR,
w1 for Element of (the carrier of SR)*;
theorem Th13:
o3 has_least_args_for o,w1 & o4 has_least_args_for o,w1 implies o3 = o4
proof
assume that
A1: o3 has_least_args_for o,w1 and
A2: o4 has_least_args_for o,w1;
A3: o ~= o3 by A1;
A4: o ~= o4 by A2;
then
A5: o3 ~= o4 by A3,Th2;
w1 <= the_arity_of o3 by A1;
then
A6: the_arity_of o4 <= the_arity_of o3 by A2,A3;
then
A7: the_result_sort_of o4 <= the_result_sort_of o3 by A5,Def7;
w1 <= the_arity_of o4 by A2;
then
A8: the_arity_of o3 <= the_arity_of o4 by A1,A4;
then
A9: the_arity_of o3 = the_arity_of o4 by A6,Th6;
the_result_sort_of o3 <= the_result_sort_of o4 by A5,A8,Def7;
then the_result_sort_of o3 = the_result_sort_of o4 by A7,ORDERS_2:2;
hence thesis by A5,A9,Def3;
end;
definition
let SR,o,w1;
assume
A1: w1 <= the_arity_of o;
func LBound(o,w1) -> OperSymbol of SR means
:Def14:
it has_least_args_for o, w1;
existence by A1,Def12;
uniqueness by Th13;
end;
theorem Th14:
for w1 st w1 <= the_arity_of o holds LBound(o,w1) has_least_rank_for o,w1
proof
let w1;
assume
A1: w1 <= the_arity_of o;
then consider o1 such that
A2: o1 has_least_rank_for o,w1 by Th11;
thus thesis by A1,A2,Def14;
end;
:: ConstOSSet of Poset, OrderSortedSets
reserve R for non empty Poset;
reserve z for non empty set;
:: just to avoid on-the-spot casting in the examples
definition
let R,z;
func ConstOSSet(R,z) -> ManySortedSet of the carrier of R equals
(the
carrier of R) --> z;
correctness
proof
the carrier of R = dom ((the carrier of R) --> z) by FUNCT_2:def 1;
hence thesis by PARTFUN1:def 2;
end;
end;
theorem Th15:
ConstOSSet(R,z) is non-empty & for s1,s2 being Element of R st
s1 <= s2 holds ConstOSSet(R,z).s1 c= ConstOSSet(R,z).s2
proof
set x = ConstOSSet(R,z);
set D = (the carrier of R) --> z;
for s being object st s in the carrier of R holds x.s is non empty
by FUNCOP_1:7;
hence x is non-empty by PBOOLE:def 13;
let s1,s2 being Element of R;
D.s1 = z by FUNCOP_1:7
.= D.s2 by FUNCOP_1:7;
hence thesis;
end;
definition
let R;
let M be ManySortedSet of R;
attr M is order-sorted means
:Def16:
for s1,s2 being Element of R st s1 <= s2 holds M.s1 c= M.s2;
end;
theorem Th16:
ConstOSSet(R,z) is order-sorted
by Th15;
registration
let R;
cluster order-sorted for ManySortedSet of R;
existence
proof
set z = the non empty set;
take ConstOSSet(R,z);
thus thesis by Th16;
end;
end;
registration
let R,z;
cluster ConstOSSet(R,z) -> order-sorted;
coherence by Th16;
end;
definition
let R be non empty Poset;
mode OrderSortedSet of R is order-sorted ManySortedSet of R;
end;
registration
let R be non empty Poset;
cluster non-empty for OrderSortedSet of R;
existence
proof
take ConstOSSet(R,{{}});
thus thesis by Th15;
end;
end;
reserve s1,s2 for SortSymbol of S,
o,o1,o2,o3 for OperSymbol of S,
w1,w2 for Element of (the carrier of S)*;
definition
let S;
let M be MSAlgebra over S;
attr M is order-sorted means
:Def17:
for s1,s2 st s1 <= s2 holds (the Sorts of M).s1 c= (the Sorts of M).s2;
end;
theorem Th17:
for M being MSAlgebra over S holds M is order-sorted iff the
Sorts of M is OrderSortedSet of S
by Def16;
reserve CH for ManySortedFunction of ConstOSSet(S,z)# * the Arity of S,
ConstOSSet(S,z) * the ResultSort of S;
definition
let S,z,CH;
func ConstOSA(S,z,CH) -> strict non-empty MSAlgebra over S means
:Def18:
the Sorts of it = ConstOSSet(S,z) & the Charact of it = CH;
existence
proof
for i being object st i in the carrier of S holds ConstOSSet(S,z).i is
non empty by FUNCOP_1:7;
then ConstOSSet(S,z) is non-empty by PBOOLE:def 13;
then reconsider T = MSAlgebra(# ConstOSSet(S,z),CH #) as strict non-empty
MSAlgebra over S by MSUALG_1:def 3;
take T;
thus thesis;
end;
uniqueness;
end;
theorem Th18:
ConstOSA(S,z,CH) is order-sorted
proof
the Sorts of ConstOSA(S,z,CH) = ConstOSSet(S,z) by Def18;
hence thesis by Th17;
end;
registration
let S;
cluster strict non-empty order-sorted for MSAlgebra over S;
existence
proof
set z = the non empty set,CH = the ManySortedFunction of ConstOSSet(S,z)# * the
Arity of S, ConstOSSet(S,z) * the ResultSort of S;
take ConstOSA(S,z,CH);
thus thesis by Th18;
end;
end;
registration
let S,z,CH;
cluster ConstOSA(S,z,CH) -> order-sorted;
coherence by Th18;
end;
definition
let S;
mode OSAlgebra of S is order-sorted MSAlgebra over S;
end;
theorem Th19:
for S being discrete OrderSortedSign, M being MSAlgebra over S
holds M is order-sorted
by ORDERS_3:1;
registration
let S be discrete OrderSortedSign;
cluster -> order-sorted for MSAlgebra over S;
coherence by Th19;
end;
reserve A for OSAlgebra of S;
theorem Th20:
w1 <= w2 implies (the Sorts of A)#.w1 c= (the Sorts of A)#.w2
proof
set iw1 = (the Sorts of A) * w1, iw2 = (the Sorts of A) * w2;
assume
A1: w1 <= w2;
then
A2: len w1 = len w2;
let x be object;
assume x in (the Sorts of A)#.w1;
then x in product(iw1) by FINSEQ_2:def 5;
then consider g being Function such that
A3: x = g and
A4: dom g = dom iw1 and
A5: for y being object st y in dom iw1 holds g.y in iw1.y by CARD_3:def 5;
A6: dom iw1 = dom w1 by Lm1
.= dom w2 by A2,FINSEQ_3:29
.= dom iw2 by Lm1;
for y being object st y in dom iw2 holds g.y in iw2.y
proof
let y be object such that
A7: y in dom iw2;
A8: y in dom w1 by A6,A7,Lm1;
then
A9: iw1.y = (the Sorts of A).(w1.y) by FUNCT_1:13;
A10: y in dom w2 by A7,Lm1;
then
A11: iw2.y = (the Sorts of A).(w2.y) by FUNCT_1:13;
reconsider s1 = w1.y, s2 = w2.y as SortSymbol of S by A8,A10,PARTFUN1:4;
s1 <= s2 by A1,A8;
then
A12: (the Sorts of A).(w1.y) c= (the Sorts of A).(w2.y) by Def17;
g.y in iw1.y by A5,A6,A7;
hence thesis by A9,A11,A12;
end;
then g in product(iw2) by A4,A6,CARD_3:def 5;
hence thesis by A3,FINSEQ_2:def 5;
end;
reserve M for MSAlgebra over S0;
:: canonical OSAlgebra for MSAlgebra
definition
let S0,M;
func OSAlg M -> strict OSAlgebra of OSSign S0 means
the Sorts of it = the Sorts of M & the Charact of it = the Charact of M;
uniqueness;
existence
proof
set S1 = OSSign S0, s0 = the Sorts of M, c0 = the Charact of M;
A1: the carrier of S0 = the carrier of S1 by Def5;
then reconsider s1 = s0 as ManySortedSet of S1;
the Arity of S0 = the Arity of S1 & the ResultSort of S1 = the
ResultSort of S0 by Def5;
then reconsider
c1 = c0 as ManySortedFunction of s1# * the Arity of S1, s1 *
the ResultSort of S1 by A1,Def5;
MSAlgebra(# s1, c1 #) is order-sorted;
hence thesis;
end;
end;
:: monotone OSAlgebra
reserve A for OSAlgebra of S;
:: Element of A should mean Element of Union the Sorts of A here ...
:: MSAFREE3:def 1; Element of A,s is defined in MSUALG_6
theorem Th21:
for w1,w2,w3 being Element of (the carrier of S)* holds w1 <= w2
& w2 <= w3 implies w1 <= w3
proof
let w1,w2,w3 be Element of (the carrier of S)*;
assume that
A1: w1 <= w2 and
A2: w2 <= w3;
A3: len w1 = len w2 by A1;
then
A4: dom w1 = dom w2 by FINSEQ_3:29;
A5: len w2 = len w3 by A2;
then
A6: dom w2 = dom w3 by FINSEQ_3:29;
for i being set st i in dom w1 for s1,s2 st s1 = w1.i & s2 = w3.i holds
s1 <= s2
proof
let i be set such that
A7: i in dom w1;
reconsider s3 = w1.i, s4 = w2.i, s5 = w3.i as SortSymbol of S by A4,A6,A7,
PARTFUN1:4;
A8: s3 <= s4 & s4 <= s5 by A1,A2,A4,A7;
let s1,s2;
assume s1 = w1.i & s2 = w3.i;
hence thesis by A8,ORDERS_2:3;
end;
hence thesis by A3,A5;
end;
definition
let S,o1,o2;
pred o1 <= o2 means
o1 ~= o2 & (the_arity_of o1) <= (the_arity_of o2
) & the_result_sort_of o1 <= the_result_sort_of o2;
reflexivity;
end;
theorem
o1 <= o2 & o2 <= o1 implies o1 = o2
proof
assume that
A1: o1 <= o2 and
A2: o2 <= o1;
the_result_sort_of o1 <= the_result_sort_of o2 & the_result_sort_of o2
<= the_result_sort_of o1 by A1,A2;
then
A3: the_result_sort_of o1 = the_result_sort_of o2 by ORDERS_2:2;
(the_arity_of o1) <= (the_arity_of o2) & (the_arity_of o2) <= (
the_arity_of o1) by A1,A2;
then
A4: the_arity_of o1 = the_arity_of o2 by Th6;
o1 ~= o2 by A1;
hence thesis by A4,A3,Def3;
end;
theorem
o1 <= o2 & o2 <= o3 implies o1 <= o3
by Th2,Th21,ORDERS_2:3;
theorem Th24:
the_result_sort_of o1 <= the_result_sort_of o2 implies Result(o1
,A) c= Result(o2,A)
proof
reconsider M = the Sorts of A as OrderSortedSet of S by Th17;
A1: Result(o2,A) = ((the Sorts of A) * the ResultSort of S).o2 by
MSUALG_1:def 5
.= (the Sorts of A).((the ResultSort of S).o2) by FUNCT_2:15
.= (the Sorts of A).(the_result_sort_of o2) by MSUALG_1:def 2;
assume the_result_sort_of o1 <= the_result_sort_of o2;
then
A2: M.(the_result_sort_of o1) c= M.(the_result_sort_of o2) by Def16;
Result(o1,A) = ((the Sorts of A) * the ResultSort of S).o1 by MSUALG_1:def 5
.= (the Sorts of A).((the ResultSort of S).o1) by FUNCT_2:15
.= (the Sorts of A).(the_result_sort_of o1) by MSUALG_1:def 2;
hence thesis by A2,A1;
end;
theorem Th25:
the_arity_of o1 <= the_arity_of o2 implies Args(o1,A) c= Args(o2 ,A)
proof
reconsider M = the Sorts of A as OrderSortedSet of S by Th17;
A1: M#.(the_arity_of o1) = M#.((the Arity of S).o1) by MSUALG_1:def 1
.= (M# * (the Arity of S)).o1 by FUNCT_2:15
.= Args(o1,A) by MSUALG_1:def 4;
A2: M#.(the_arity_of o2) = M#.((the Arity of S).o2) by MSUALG_1:def 1
.= (M# * (the Arity of S)).o2 by FUNCT_2:15
.= Args(o2,A) by MSUALG_1:def 4;
assume the_arity_of o1 <= the_arity_of o2;
hence thesis by A1,A2,Th20;
end;
theorem
o1 <= o2 implies Args(o1,A) c= Args(o2,A) & Result(o1,A) c= Result(o2, A )
by Th24,Th25;
:: OSAlgebra is monotone iff the interpretation of the same symbol on
:: widening sorts coincides
:: the definition would be nicer as function inclusion (see TEqMon)
:: without the restriction to Args(o1,A), but the permissiveness
:: of FUNCT_2:def 1 spoils that
definition
let S,A;
attr A is monotone means
for o1,o2 st o1 <= o2 holds Den(o2,A)|Args( o1,A) = Den(o1,A);
end;
theorem Th27:
for A being non-empty OSAlgebra of S holds A is monotone iff for
o1,o2 st o1 <= o2 holds Den(o1,A) c= Den(o2,A)
proof
let A be non-empty OSAlgebra of S;
hereby
assume
A1: A is monotone;
let o1,o2;
assume o1 <= o2;
then Den(o2,A)|Args(o1,A) = Den(o1,A) by A1;
hence Den(o1,A) c= Den(o2,A) by RELAT_1:59;
end;
assume
A2: for o1,o2 st o1 <= o2 holds Den(o1,A) c= Den(o2,A);
let o1,o2 such that
A3: o1 <= o2;
dom Den(o1,A) = Args(o1,A) by FUNCT_2:def 1;
hence Den(o2,A)|Args(o1,A) = Den(o1,A)|Args(o1,A) by A2,A3,GRFUNC_1:27
.= Den(o1,A);
end;
theorem
(S is discrete or S is op-discrete) implies A is monotone
proof
assume
A1: S is discrete or S is op-discrete;
let o1,o2;
assume that
A2: o1 ~= o2 and
A3: (the_arity_of o1) <= (the_arity_of o2) & the_result_sort_of o1 <=
the_result_sort_of o2;
o1 = o2
proof
per cases by A1;
suppose
S is discrete;
hence thesis by A2,A3,Th8;
end;
suppose
S is op-discrete;
hence thesis by A2,Th3;
end;
end;
hence thesis;
end;
:: TrivialOSA(S,z,z1) interprets all funcs as one constant
definition
let S,z;
let z1 be Element of z;
func TrivialOSA(S,z,z1) -> strict OSAlgebra of S means
:Def22:
the Sorts of
it = ConstOSSet(S,z) & for o holds Den(o,it) = Args(o,it) --> z1;
existence
proof
set c = ConstOSSet(S,z);
deffunc ch1(Element of the carrier' of S) = ((c# * the Arity of S).$1) -->
(z1 qua set);
consider ch2 being Function such that
A1: dom ch2 = the carrier' of S & for x being Element of (the carrier'
of S) holds ch2.x = ch1(x) from FUNCT_1:sch 4;
reconsider ch4 = ch2 as ManySortedSet of (the carrier' of S) by A1,
PARTFUN1:def 2,RELAT_1:def 18;
for i being object st i in (the carrier' of S) holds ch4.i is Function of
(ConstOSSet(S,z)# * the Arity of S).i, (ConstOSSet(S,z) * the ResultSort of S).
i
proof
let i be object;
assume i in the carrier' of S;
then reconsider o=i as OperSymbol of S;
(the ResultSort of S).o in the carrier of S;
then
A2: o in ((the ResultSort of S)"(the carrier of S)) by FUNCT_2:38;
(ConstOSSet(S,z) * the ResultSort of S).o = (((the ResultSort of S)"
(the carrier of S)) --> z).o by FUNCOP_1:19
.= z by A2,FUNCOP_1:7;
then
A3: {z1} c= (ConstOSSet(S,z) * the ResultSort of S).i by ZFMISC_1:31;
ch4.i = ch1(o) by A1;
hence thesis by A3,FUNCT_2:7;
end;
then reconsider ch3 = ch4 as ManySortedFunction of (ConstOSSet(S,z)# * the
Arity of S), (ConstOSSet(S,z) * the ResultSort of S) by PBOOLE:def 15;
take T = ConstOSA(S,z,ch3);
thus
A4: the Sorts of T = ConstOSSet(S,z) by Def18;
let o;
Den(o,T) = (the Charact of T).o by MSUALG_1:def 6
.= ch3.o by Def18
.= ((c# * the Arity of S).o) --> z1 by A1
.= Args(o,T) --> z1 by A4,MSUALG_1:def 4;
hence thesis;
end;
uniqueness
proof
let T1,T2 be strict OSAlgebra of S;
assume that
A5: the Sorts of T1 = ConstOSSet(S,z) and
A6: for o holds Den(o,T1) = Args(o,T1) --> z1;
assume that
A7: the Sorts of T2 = ConstOSSet(S,z) and
A8: for o holds Den(o,T2) = Args(o,T2) --> z1;
now
let o1 be object;
assume o1 in the carrier' of S;
then reconsider o = o1 as OperSymbol of S;
thus (the Charact of T1).o1 = Den(o,T1) by MSUALG_1:def 6
.= Args(o,T1) --> z1 by A6
.= ((ConstOSSet(S,z)# * the Arity of S).o) --> z1 by A5,MSUALG_1:def 4
.= Args(o,T2) --> z1 by A7,MSUALG_1:def 4
.= Den(o,T2) by A8
.= (the Charact of T2).o1 by MSUALG_1:def 6;
end;
hence thesis by A5,A7,PBOOLE:3;
end;
end;
theorem Th29:
for z1 being Element of z holds TrivialOSA(S,z,z1) is non-empty
& TrivialOSA(S,z,z1) is monotone
proof
let z1 be Element of z;
set A = TrivialOSA(S,z,z1);
the Sorts of A = ConstOSSet(S,z) by Def22;
then
A1: the Sorts of A is non-empty by Th15;
hence A is non-empty by MSUALG_1:def 3;
reconsider A1 = A as non-empty OSAlgebra of S by A1,MSUALG_1:def 3;
for o1,o2 st o1 <= o2 holds Den(o1,A1) c= Den(o2,A1)
proof
let o1,o2;
A2: Args(o1,A) = ((the Sorts of A)# * the Arity of S).o1 by MSUALG_1:def 4
.= (the Sorts of A)#.((the Arity of S).o1) by FUNCT_2:15
.= (the Sorts of A)#.(the_arity_of o1) by MSUALG_1:def 1;
A3: Args(o2,A) = ((the Sorts of A)# * the Arity of S).o2 by MSUALG_1:def 4
.= (the Sorts of A)#.((the Arity of S).o2) by FUNCT_2:15
.= (the Sorts of A)#.(the_arity_of o2) by MSUALG_1:def 1;
assume o1 <= o2;
then
A4: (the_arity_of o1) <= (the_arity_of o2);
Den(o1,A) = Args(o1,A) --> z1 & Den(o2,A) = Args(o2,A) --> z1 by Def22;
hence thesis by A4,A2,A3,Th20,FUNCT_4:4;
end;
hence thesis by Th27;
end;
registration
let S;
cluster monotone strict non-empty for OSAlgebra of S;
existence
proof
set z = the non empty set;
set z1 = the Element of z;
take TrivialOSA(S,z,z1);
thus thesis by Th29;
end;
end;
registration
let S,z;
let z1 be Element of z;
cluster TrivialOSA(S,z,z1) -> monotone non-empty;
coherence by Th29;
end;
:: OperNames, OperName, Name
reserve op1,op2 for OperSymbol of S;
definition
let S;
func OperNames S -> non empty (Subset-Family of the carrier' of S) equals
Class the Overloading of S;
coherence;
end;
registration
let S;
cluster -> non empty for Element of OperNames S;
coherence
proof
let X be Element of OperNames S;
ex x being object
st x in the carrier' of S & X = Class(the Overloading of
S,x) by EQREL_1:def 3;
hence thesis by EQREL_1:20;
end;
end;
definition
let S;
mode OperName of S is Element of OperNames S;
end;
definition
let S,op1;
func Name op1 -> OperName of S equals
Class(the Overloading of S,op1);
coherence by EQREL_1:def 3;
end;
theorem Th30:
op1 ~= op2 iff op2 in Class(the Overloading of S,op1)
proof
op1 ~= op2 iff [op2,op1] in the Overloading of S by Def2;
hence thesis by EQREL_1:19;
end;
theorem Th31:
op1 ~= op2 iff Name op1 = Name op2
proof
op2 in Class(the Overloading of S,op1) iff Class(the Overloading of S,
op1) = Class(the Overloading of S,op2) by EQREL_1:23;
hence thesis by Th30;
end;
theorem
for X being set holds X is OperName of S iff ex op1 st X = Name op1
proof
let X be set;
hereby
assume X is OperName of S;
then consider x being object such that
A1: x in the carrier' of S and
A2: X = Class(the Overloading of S,x) by EQREL_1:def 3;
reconsider x1 = x as OperSymbol of S by A1;
take x1;
thus X = Name x1 by A2;
end;
given op1 such that
A3: X = Name op1;
thus thesis by A3;
end;
definition
let S;
let o be OperName of S;
redefine mode Element of o -> OperSymbol of S;
coherence
proof
let x be Element of o;
thus thesis;
end;
end;
theorem Th33:
for on being OperName of S, op being OperSymbol of S holds op is
Element of on iff Name op = on
proof
let on be OperName of S, op1 be OperSymbol of S;
hereby
assume op1 is Element of on;
then reconsider op = op1 as Element of on;
(ex op2 being object st op2 in the carrier' of S & on = Class (the
Overloading of S,op2) )& Name op = Class(the Overloading of S,op) by
EQREL_1:def 3;
hence Name op1 = on by EQREL_1:23;
end;
assume Name op1 = on;
hence thesis by EQREL_1:20;
end;
theorem Th34:
for SR being regular monotone OrderSortedSign, op1,op2 being
OperSymbol of SR, w being Element of (the carrier of SR)* st op1 ~= op2 & w <=
the_arity_of op1 & w <= the_arity_of op2 holds LBound(op1,w) = LBound(op2,w)
proof
let SR be regular monotone OrderSortedSign, op1,op2 be OperSymbol of SR, w
be Element of (the carrier of SR)* such that
A1: op1 ~= op2 and
A2: w <= the_arity_of op1 and
A3: w <= the_arity_of op2;
set Lo1 = LBound(op1,w), Lo2 = LBound(op2,w);
A4: LBound(op1,w) has_least_args_for op1,w by A2,Def14;
then
A5: op1 ~= Lo1;
A6: LBound(op2,w) has_least_args_for op2,w by A3,Def14;
then
A7: for o2 being OperSymbol of SR st op2 ~= o2 & w <= the_arity_of o2 holds
the_arity_of Lo2 <= the_arity_of o2;
op2 ~= Lo2 by A6;
then
A8: op1 ~= Lo2 by A1,Th2;
then
A9: Lo1 ~= Lo2 by A5,Th2;
w <= the_arity_of Lo1 by A4;
then
A10: the_arity_of Lo2 <= the_arity_of Lo1 by A1,A5,A7,Th2;
then
A11: the_result_sort_of Lo2 <= the_result_sort_of Lo1 by A9,Def7;
w <= the_arity_of Lo2 by A6;
then
A12: the_arity_of Lo1 <= the_arity_of Lo2 by A4,A8;
then
A13: the_arity_of Lo1 = the_arity_of Lo2 by A10,Th6;
the_result_sort_of Lo1 <= the_result_sort_of Lo2 by A9,A12,Def7;
then the_result_sort_of Lo1 = the_result_sort_of Lo2 by A11,ORDERS_2:2;
hence thesis by A9,A13,Def3;
end;
definition
let SR be regular monotone OrderSortedSign, on be OperName of SR, w be
Element of (the carrier of SR)*;
assume
A1: ex op being Element of on st w <= the_arity_of op;
func LBound(on,w) -> Element of on means
for op being Element of on st w <= the_arity_of op holds it = LBound(op,w);
existence
proof
consider op being Element of on such that
A2: w <= the_arity_of op by A1;
set Lo = LBound(op,w);
LBound(op,w) has_least_args_for op,w by A2,Def14;
then op ~= Lo;
then
A3: Name(op) = Name Lo by Th31;
then
A4: Name Lo = on by Th33;
then reconsider Lo as Element of on by Th33;
take Lo;
let op1 be Element of on such that
A5: w <= the_arity_of op1;
Name op1 = on by Th33;
then op1 ~= op by A3,A4,Th31;
hence thesis by A2,A5,Th34;
end;
uniqueness
proof
let op1,op2 be Element of on such that
A6: for op3 being Element of on st w <= the_arity_of op3 holds op1 =
LBound(op3,w) and
A7: for op3 being Element of on st w <= the_arity_of op3 holds op2 =
LBound(op3,w);
consider op being Element of on such that
A8: w <= the_arity_of op by A1;
op1 = LBound(op,w) by A8,A6;
hence thesis by A8,A7;
end;
end;
theorem
for S being regular monotone OrderSortedSign, o being OperSymbol of
S, w1 being Element of (the carrier of S)* st w1 <= the_arity_of o holds LBound
(o,w1) <= o
proof
let S being regular monotone OrderSortedSign, o being OperSymbol of S, w1
being Element of (the carrier of S)* such that
A1: w1 <= the_arity_of o;
set lo = LBound(o,w1);
A2: lo has_least_rank_for o,w1 by A1,Th14;
then lo has_least_sort_for o,w1;
then
A3: the_result_sort_of lo <= the_result_sort_of o by A1;
A4: lo has_least_args_for o,w1 by A2;
then
A5: o ~= lo;
the_arity_of lo <= the_arity_of o by A1,A4;
hence thesis by A5,A3;
end;