设a、月、γ∈V,∈R (1)a+B=B+a (2)(a+B)+y=a+(B+) (3)30∈V,对a∈V,都有a+0=a (4)a∈V,3B∈V,都有a+B=0 (5)1a=a (6)A(10)=(4)a (7)(+)0=a+ (8)(a+B)=a+AB(1) (2) ( ) ( ) (3) (4) (5) 1 (6) ( ) ( ) (7) ( ) (8) ( ) λ μ + = + + + = + + + = + = = = + = + + = + α β γ V R α β β α α β γ α β γ 0 V α V α 0 α α V β V α β 0 α α α α α α α α β α β 设 、、 , 、 ,对 ,都有 , ,都有