Metadata aliases: [] shorthands: {} created: 2022-11-12 20:47:03 modified: 2022-11-12 21:00:11 Statement: Let be a monoid or group with identity element and let and be invertible elements of , where and are the inverses. Then is invertible and its inverse is given by .
aliases: [] shorthands: {} created: 2022-11-12 20:47:03 modified: 2022-11-12 21:00:11
By using associativity and that is the identity element:
Also:
Since both evaluate to , QED.