:: XBOOLE_1 semantic presentation

begin

theorem :: XBOOLE_1:1
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) & Y : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:2
for X being ( ( ) ( ) set ) holds {} : ( ( ) ( empty ) set ) c= X : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:3
for X being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= {} : ( ( ) ( empty ) set ) holds
X : ( ( ) ( ) set ) = {} : ( ( ) ( empty ) set ) ;

theorem :: XBOOLE_1:4
for X, Y, Z being ( ( ) ( ) set ) holds (X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) \/ (Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:5
for X, Y, Z being ( ( ) ( ) set ) holds (X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ (Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:6
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \/ (X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:7
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) c= X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:8
for X, Z, Y being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) & Y : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:9
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:10
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:11
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:12
for X, Y being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = Y : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:13
for X, Y, Z, V being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) & Z : ( ( ) ( ) set ) c= V : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) \/ V : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:14
for Y, X, Z being ( ( ) ( ) set ) st Y : ( ( ) ( ) set ) c= X : ( ( ) ( ) set ) & Z : ( ( ) ( ) set ) c= X : ( ( ) ( ) set ) & ( for V being ( ( ) ( ) set ) st Y : ( ( ) ( ) set ) c= V : ( ( ) ( ) set ) & Z : ( ( ) ( ) set ) c= V : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) c= V : ( ( ) ( ) set ) ) holds
X : ( ( ) ( ) set ) = Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:15
for X, Y being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = {} : ( ( ) ( empty ) set ) holds
X : ( ( ) ( ) set ) = {} : ( ( ) ( empty ) set ) ;

theorem :: XBOOLE_1:16
for X, Y, Z being ( ( ) ( ) set ) holds (X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) /\ (Y : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:17
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= X : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:18
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:19
for Z, X, Y being ( ( ) ( ) set ) st Z : ( ( ) ( ) set ) c= X : ( ( ) ( ) set ) & Z : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) holds
Z : ( ( ) ( ) set ) c= X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:20
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) & X : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) & ( for V being ( ( ) ( ) set ) st V : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) & V : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) holds
V : ( ( ) ( ) set ) c= X : ( ( ) ( ) set ) ) holds
X : ( ( ) ( ) set ) = Y : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:21
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) /\ (X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:22
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \/ (X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:23
for X, Y, Z being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) /\ (Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ (X : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:24
for X, Y, Z being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \/ (Y : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) /\ (X : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:25
for X, Y, Z being ( ( ) ( ) set ) holds ((X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ (Y : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ (Z : ( ( ) ( ) set ) /\ X : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = ((X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) /\ (Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) /\ (Z : ( ( ) ( ) set ) \/ X : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:26
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:27
for X, Y, Z, V being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) & Z : ( ( ) ( ) set ) c= V : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) /\ V : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:28
for X, Y being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:29
for X, Y, Z being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= X : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:30
for X, Z, Y being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) \/ (Y : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:31
for X, Y, Z being ( ( ) ( ) set ) holds (X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ (X : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:32
for X, Y being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = Y : ( ( ) ( ) set ) \ X : ( ( ) ( ) set ) : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) = Y : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:33
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:34
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) holds
Z : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) \ X : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:35
for X, Y, Z, V being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) & Z : ( ( ) ( ) set ) c= V : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) \ V : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:36
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= X : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:37
for X, Y being ( ( ) ( ) set ) holds
( X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = {} : ( ( ) ( empty ) set ) iff X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) ) ;

theorem :: XBOOLE_1:38
for X, Y being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) \ X : ( ( ) ( ) set ) : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) = {} : ( ( ) ( empty ) set ) ;

theorem :: XBOOLE_1:39
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \/ (Y : ( ( ) ( ) set ) \ X : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:40
for X, Y being ( ( ) ( ) set ) holds (X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:41
for X, Y, Z being ( ( ) ( ) set ) holds (X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) \ (Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:42
for X, Y, Z being ( ( ) ( ) set ) holds (X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ (Y : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:43
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:44
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:45
for X, Y being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) holds
Y : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) \/ (Y : ( ( ) ( ) set ) \ X : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:46
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \ (X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = {} : ( ( ) ( empty ) set ) ;

theorem :: XBOOLE_1:47
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \ (X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:48
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \ (X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:49
for X, Y, Z being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) /\ (Y : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:50
for X, Y, Z being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) /\ (Y : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \ (X : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:51
for X, Y being ( ( ) ( ) set ) holds (X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ (X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:52
for X, Y, Z being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \ (Y : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ (X : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:53
for X, Y, Z being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \ (Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) /\ (X : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:54
for X, Y, Z being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \ (Y : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ (X : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:55
for X, Y being ( ( ) ( ) set ) holds (X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \ (X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ (Y : ( ( ) ( ) set ) \ X : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:56
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c< Y : ( ( ) ( ) set ) & Y : ( ( ) ( ) set ) c< Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) c< Z : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:57
for X, Y being ( ( ) ( ) set ) holds
( not X : ( ( ) ( ) set ) c< Y : ( ( ) ( ) set ) or not Y : ( ( ) ( ) set ) c< X : ( ( ) ( ) set ) ) ;

theorem :: XBOOLE_1:58
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c< Y : ( ( ) ( ) set ) & Y : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) c< Z : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:59
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) & Y : ( ( ) ( ) set ) c< Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) c< Z : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:60
for X, Y being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) holds
not Y : ( ( ) ( ) set ) c< X : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:61
for X being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) <> {} : ( ( ) ( empty ) set ) holds
{} : ( ( ) ( empty ) set ) c< X : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:62
for X being ( ( ) ( ) set ) holds not X : ( ( ) ( ) set ) c< {} : ( ( ) ( empty ) set ) ;

theorem :: XBOOLE_1:63
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) & Y : ( ( ) ( ) set ) misses Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) misses Z : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:64
for A, X, B, Y being ( ( ) ( ) set ) st A : ( ( ) ( ) set ) c= X : ( ( ) ( ) set ) & B : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) & X : ( ( ) ( ) set ) misses Y : ( ( ) ( ) set ) holds
A : ( ( ) ( ) set ) misses B : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:65
for X being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) misses {} : ( ( ) ( empty ) set ) ;

theorem :: XBOOLE_1:66
for X being ( ( ) ( ) set ) holds
( X : ( ( ) ( ) set ) meets X : ( ( ) ( ) set ) iff X : ( ( ) ( ) set ) <> {} : ( ( ) ( empty ) set ) ) ;

theorem :: XBOOLE_1:67
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) & X : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) & Y : ( ( ) ( ) set ) misses Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) = {} : ( ( ) ( empty ) set ) ;

theorem :: XBOOLE_1:68
for Y, Z being ( ( ) ( ) set )
for A being ( ( non empty ) ( non empty ) set ) st A : ( ( non empty ) ( non empty ) set ) c= Y : ( ( ) ( ) set ) & A : ( ( non empty ) ( non empty ) set ) c= Z : ( ( ) ( ) set ) holds
Y : ( ( ) ( ) set ) meets Z : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:69
for Y being ( ( ) ( ) set )
for A being ( ( non empty ) ( non empty ) set ) st A : ( ( non empty ) ( non empty ) set ) c= Y : ( ( ) ( ) set ) holds
A : ( ( non empty ) ( non empty ) set ) meets Y : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:70
for X, Y, Z being ( ( ) ( ) set ) holds
( ( X : ( ( ) ( ) set ) meets Y : ( ( ) ( ) set ) or X : ( ( ) ( ) set ) meets Z : ( ( ) ( ) set ) ) iff X : ( ( ) ( ) set ) meets Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ) ;

theorem :: XBOOLE_1:71
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = Z : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) & X : ( ( ) ( ) set ) misses Y : ( ( ) ( ) set ) & Z : ( ( ) ( ) set ) misses Y : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) = Z : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:72
for X9, Y9, X, Y being ( ( ) ( ) set ) st X9 : ( ( ) ( ) set ) \/ Y9 : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) & X : ( ( ) ( ) set ) misses X9 : ( ( ) ( ) set ) & Y : ( ( ) ( ) set ) misses Y9 : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) = Y9 : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:73
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) & X : ( ( ) ( ) set ) misses Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:74
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) meets Y : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) meets Y : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:75
for X, Y being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) meets Y : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) meets Y : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:76
for Y, Z, X being ( ( ) ( ) set ) st Y : ( ( ) ( ) set ) misses Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) misses X : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:77
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) meets Y : ( ( ) ( ) set ) & X : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) meets Y : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:78
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) misses Y : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) /\ (Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:79
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) misses Y : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:80
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) misses Y : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) misses Y : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:81
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) misses Y : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) holds
Y : ( ( ) ( ) set ) misses X : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:82
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) misses Y : ( ( ) ( ) set ) \ X : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:83
for X, Y being ( ( ) ( ) set ) holds
( X : ( ( ) ( ) set ) misses Y : ( ( ) ( ) set ) iff X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) ) ;

theorem :: XBOOLE_1:84
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) meets Y : ( ( ) ( ) set ) & X : ( ( ) ( ) set ) misses Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) meets Y : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:85
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) misses Z : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:86
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) & X : ( ( ) ( ) set ) misses Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) c= Y : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:87
for Y, Z, X being ( ( ) ( ) set ) st Y : ( ( ) ( ) set ) misses Z : ( ( ) ( ) set ) holds
(X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:88
for X, Y being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) misses Y : ( ( ) ( ) set ) holds
(X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:89
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) misses X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:90
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \ (X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) misses Y : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:91
for X, Y, Z being ( ( ) ( ) set ) holds (X : ( ( ) ( ) set ) \+\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \+\ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) \+\ (Y : ( ( ) ( ) set ) \+\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:92
for X being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \+\ X : ( ( ) ( ) set ) : ( ( ) ( ) set ) = {} : ( ( ) ( empty ) set ) ;

theorem :: XBOOLE_1:93
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \+\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ (X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:94
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \+\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \+\ (X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:95
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \+\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \+\ (X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:96
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= X : ( ( ) ( ) set ) \+\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:97
for X, Y, Z being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) & Y : ( ( ) ( ) set ) \ X : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) \+\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= Z : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:98
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) \+\ (Y : ( ( ) ( ) set ) \ X : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:99
for X, Y, Z being ( ( ) ( ) set ) holds (X : ( ( ) ( ) set ) \+\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \ (Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ (Y : ( ( ) ( ) set ) \ (X : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:100
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) \+\ (X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:101
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \+\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \ (X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:102
for X, Y, Z being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) \ (Y : ( ( ) ( ) set ) \+\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \ (Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ ((X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:103
for X, Y being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) misses X : ( ( ) ( ) set ) \+\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:104
for X, Y being ( ( ) ( ) set ) holds
( ( X : ( ( ) ( ) set ) c< Y : ( ( ) ( ) set ) or X : ( ( ) ( ) set ) = Y : ( ( ) ( ) set ) or Y : ( ( ) ( ) set ) c< X : ( ( ) ( ) set ) ) iff X : ( ( ) ( ) set ) ,Y : ( ( ) ( ) set ) are_c=-comparable ) ;

begin

theorem :: XBOOLE_1:105
for X, Y being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c< Y : ( ( ) ( ) set ) holds
Y : ( ( ) ( ) set ) \ X : ( ( ) ( ) set ) : ( ( ) ( ) set ) <> {} : ( ( ) ( empty ) set ) ;

theorem :: XBOOLE_1:106
for X, A, B being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= A : ( ( ) ( ) set ) \ B : ( ( ) ( ) set ) : ( ( ) ( ) set ) holds
( X : ( ( ) ( ) set ) c= A : ( ( ) ( ) set ) & X : ( ( ) ( ) set ) misses B : ( ( ) ( ) set ) ) ;

theorem :: XBOOLE_1:107
for X, A, B being ( ( ) ( ) set ) holds
( X : ( ( ) ( ) set ) c= A : ( ( ) ( ) set ) \+\ B : ( ( ) ( ) set ) : ( ( ) ( ) set ) iff ( X : ( ( ) ( ) set ) c= A : ( ( ) ( ) set ) \/ B : ( ( ) ( ) set ) : ( ( ) ( ) set ) & X : ( ( ) ( ) set ) misses A : ( ( ) ( ) set ) /\ B : ( ( ) ( ) set ) : ( ( ) ( ) set ) ) ) ;

theorem :: XBOOLE_1:108
for X, A, Y being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= A : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= A : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:109
for X, A, Y being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= A : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= A : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:110
for X, A, Y being ( ( ) ( ) set ) st X : ( ( ) ( ) set ) c= A : ( ( ) ( ) set ) & Y : ( ( ) ( ) set ) c= A : ( ( ) ( ) set ) holds
X : ( ( ) ( ) set ) \+\ Y : ( ( ) ( ) set ) : ( ( ) ( ) set ) c= A : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:111
for X, Z, Y being ( ( ) ( ) set ) holds (X : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \ (Y : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:112
for X, Z, Y being ( ( ) ( ) set ) holds (X : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \+\ (Y : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) \+\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:113
for X, Y, Z, V being ( ( ) ( ) set ) holds ((X : ( ( ) ( ) set ) \/ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ V : ( ( ) ( ) set ) : ( ( ) ( ) set ) = X : ( ( ) ( ) set ) \/ ((Y : ( ( ) ( ) set ) \/ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ V : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:114
for A, B, C, D being ( ( ) ( ) set ) st A : ( ( ) ( ) set ) misses D : ( ( ) ( ) set ) & B : ( ( ) ( ) set ) misses D : ( ( ) ( ) set ) & C : ( ( ) ( ) set ) misses D : ( ( ) ( ) set ) holds
(A : ( ( ) ( ) set ) \/ B : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ C : ( ( ) ( ) set ) : ( ( ) ( ) set ) misses D : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:115
for A being ( ( ) ( ) set ) holds not A : ( ( ) ( ) set ) c< {} : ( ( ) ( empty ) set ) ;

theorem :: XBOOLE_1:116
for X, Y, Z being ( ( ) ( ) set ) holds X : ( ( ) ( ) set ) /\ (Y : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (X : ( ( ) ( ) set ) /\ Y : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) /\ (X : ( ( ) ( ) set ) /\ Z : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;

theorem :: XBOOLE_1:117
for P, G, C being ( ( ) ( ) set ) st C : ( ( ) ( ) set ) c= G : ( ( ) ( ) set ) holds
P : ( ( ) ( ) set ) \ C : ( ( ) ( ) set ) : ( ( ) ( ) set ) = (P : ( ( ) ( ) set ) \ G : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) \/ (P : ( ( ) ( ) set ) /\ (G : ( ( ) ( ) set ) \ C : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) : ( ( ) ( ) set ) ;