2.1.7.
Show the uniqueness of the additive identity and the additive inverse using only (A1), (A2), (A3). (This is tricky; the opening pages of some books on group theory will help.)
Show the uniqueness of the additive identity and the additive inverse using only (A1), (A2), (A3). (This is tricky; the opening pages of some books on group theory will help.)