, , , , .
R1 = { r1 }, R2 = { r2}, r1 r2 - R1 R2,
R1 R2 = { r | r R1 r R2}.
r , "".
. R1 R2, , . R3 , , .
R1 | |
M1 | |
2 | |
3 | |
1 | |
3 | |
1 | |
3 | |
R2 | |
M1 | |
3 | |
4 | |
2 |
R3 | |
M1 | |
2 | |
3 | |
1 | |
3 | |
1 | |
3 | |
4 | |
2 |
, , . R1 R2:
R3 = R1 R2 ={ r | r R1 r R2 }
( "").
R4 , .
R4 | |
M1 | |
3 | |
3 |
R1 R2 , , R1 R2:
R5 =R1 \R2 ={r | r R1 r R2}
R5 , 1, R6 , 2.
R6 =R2 \ R1 ={r | r R2 r R1 }
R2 | |||
3 | |||
R5 | |||
2 | |||
1 | |||
1 | |||
3 | |||
R6 | |
4 | |
2 |
, , , , . , , R5 R6.
, . , : , , , .
|
|
, .
- . , , R1 R2, . , , , .
, , c = <c1, c2,..., cn> q = <q1, q2,..., qm> , . c q (c, q).
(c, q) = <c1, c2,..., cn, q1, q2,..., qm>
n , m q.
. .
R1 n
SR1 = (A1, A2,..., An),
R2 m
SR2 = (B1, B2,..., Bm),
R3 n+m
SR3 = (A1, A2,..., An, B1, B2,..., Bm),
, r R1 q R2.
R1 = { r }, R2 = { q }
R1 R2 = {(r, q) | r R1 q R2}
. . . , . , .
- , , , .
(R1 R2) \ (R1 \ R2) \ (R2 \ R1)
, - .
, .