* If this is successful, then the assumption that the proposition is false, is, itself, false. Hence, the proposition is true. |
* If this is successful, then the assumption that the proposition is false, is, itself, false. Hence, the proposition is true. |
I. For all a. b belonging to (G,*), if a*b=e, then a=b^-1 and b=a^-1. |
I. For all a. b belonging to a GrouP (G,*), if a*b=e, then a=b^-1 and b=a^-1. |
II. For all a,b belonging to (G,*), (a*b)^-1=b^-1*a^-1. |
II. For all a,b belonging to a GrouP (G,*), (a*b)^-1=b^-1*a^-1. |
III. For all a belonging to (G,*), (a^-1)^-1=a. |
III. For all a belonging to a GrouP (G,*), (a^-1)^-1=a. |
IV. For all a,x,y, belonging to (G,*), if a*x=a*y, then x=y, and if x*a=y*a, then x=y. |
IV. For all a,x,y, belonging to GrouP (G,*), if a*x=a*y, then x=y, and if x*a=y*a, then x=y. |