( 1 . 2 . 3 ) 1
1431/1432



+ (( 2 . 3 )) 1 1432.





(( )) 1 1431_1432.





(( )) 1 1431_1432.





(( )) 1 1431_1432.





(( )) 1 1431_1432.





+ (( )) 1 1431_1432.





+ (( )) 1 1431_1432.





+ (( )) 1 1431_1432.





+ (( )) 1 1431_1432.





(( 2 . 3 )) 1.






1 1431_1432.





(( 1 )) + .





(( 1 )) + .





1 1431_1432.





(( ))





.





3 1.