set at = the Attributes of R;
set X = { [A,B] where A, B is Subset of the Attributes of R : A >|> B,R } ;
{ [A,B] where A, B is Subset of the Attributes of R : A >|> B,R } c= [:(bool the Attributes of R),(bool the Attributes of R):]
proof
let x be
object ;
TARSKI:def 3 ( not x in { [A,B] where A, B is Subset of the Attributes of R : A >|> B,R } or x in [:(bool the Attributes of R),(bool the Attributes of R):] )
assume
x in { [A,B] where A, B is Subset of the Attributes of R : A >|> B,R }
;
x in [:(bool the Attributes of R),(bool the Attributes of R):]
then
ex
A,
B being
Subset of the
Attributes of
R st
(
x = [A,B] &
A >|> B,
R )
;
hence
x in [:(bool the Attributes of R),(bool the Attributes of R):]
by ZFMISC_1:def 2;
verum
end;
hence
{ [A,B] where A, B is Subset of the Attributes of R : A >|> B,R } is Dependency-set of the Attributes of R
; verum