6.

, , :

1. = b, , b. 2 = b2 , , , . . , . 3 = b3 , ;

2. . , ;

3. . . . . . . .., , . . . .;

4. . . . X, - .. Y = X + Z, Z .., . , .. Y, X. ( Z ), . X.

1865 . .

1921 . , "" , .

1948 . . "" , , , , " " .

► 4

= 5

> 3?