begin
scheme
KuratowskiFunction{
F1()
-> set ,
F2(
set )
-> set } :
provided
A1:
for
e being
set st
e in F1() holds
F2(
e)
<> {}
definition
let I be
set ;
coherence
I --> {} is ManySortedSet of I
;
correctness
;
let X,
Y be
ManySortedSet of
I;
existence
ex b1 being ManySortedSet of I st
for i being set st i in I holds
b1 . i = (X . i) \/ (Y . i)
uniqueness
for b1, b2 being ManySortedSet of I st ( for i being set st i in I holds
b1 . i = (X . i) \/ (Y . i) ) & ( for i being set st i in I holds
b2 . i = (X . i) \/ (Y . i) ) holds
b1 = b2
commutativity
for b1, X, Y being ManySortedSet of I st ( for i being set st i in I holds
b1 . i = (X . i) \/ (Y . i) ) holds
for i being set st i in I holds
b1 . i = (Y . i) \/ (X . i)
;
idempotence
for X being ManySortedSet of I
for i being set st i in I holds
X . i = (X . i) \/ (X . i)
;
existence
ex b1 being ManySortedSet of I st
for i being set st i in I holds
b1 . i = (X . i) /\ (Y . i)
uniqueness
for b1, b2 being ManySortedSet of I st ( for i being set st i in I holds
b1 . i = (X . i) /\ (Y . i) ) & ( for i being set st i in I holds
b2 . i = (X . i) /\ (Y . i) ) holds
b1 = b2
commutativity
for b1, X, Y being ManySortedSet of I st ( for i being set st i in I holds
b1 . i = (X . i) /\ (Y . i) ) holds
for i being set st i in I holds
b1 . i = (Y . i) /\ (X . i)
;
idempotence
for X being ManySortedSet of I
for i being set st i in I holds
X . i = (X . i) /\ (X . i)
;
existence
ex b1 being ManySortedSet of I st
for i being set st i in I holds
b1 . i = (X . i) \ (Y . i)
uniqueness
for b1, b2 being ManySortedSet of I st ( for i being set st i in I holds
b1 . i = (X . i) \ (Y . i) ) & ( for i being set st i in I holds
b2 . i = (X . i) \ (Y . i) ) holds
b1 = b2
symmetry
for X, Y being ManySortedSet of I st ( for i being set st i in I holds
X . i meets Y . i ) holds
for i being set st i in I holds
Y . i meets X . i
;
symmetry
for X, Y being ManySortedSet of I st ( for i being set st i in I holds
X . i misses Y . i ) holds
for i being set st i in I holds
Y . i misses X . i
;
end;
begin
Lm1:
for I being set
for X, Y being ManySortedSet of I st X c= Y & Y c= X holds
X = Y
begin
begin
begin
begin
begin
begin
begin
scheme
MSSEx{
F1()
-> set ,
P1[
set ,
set ] } :
provided
A1:
for
i being
set st
i in F1() holds
ex
j being
set st
P1[
i,
j]
begin