Hello,
I have this structure \(\displaystyle \mathcal{G} = \{ \mathbb{R}, +^ \mathcal{G}, 0^ \mathcal{G} \}\) and I used this automorphism \(\displaystyle
\psi\,\colon = x \mapsto -x\) to prove something (that "<" cannot be expressed with this structure). Which equalities makes psi to be an automorphism?
Thx
I have this structure \(\displaystyle \mathcal{G} = \{ \mathbb{R}, +^ \mathcal{G}, 0^ \mathcal{G} \}\) and I used this automorphism \(\displaystyle
\psi\,\colon = x \mapsto -x\) to prove something (that "<" cannot be expressed with this structure). Which equalities makes psi to be an automorphism?
Thx