Definition:Ordered Structure Automorphism
Definition
Let $\left({S, \circ, \preceq}\right)$ be an ordered structures.
Let $\phi: S \to S$ be an ordered structure isomorphism from $S$ to itself.
Then $\phi$ is an ordered structure automorphism.
Ordered Semigroup Automorphism
Let $\struct {S, \circ, \preceq}$ be an ordered semigroup.
An ordered semigroup automorphism from $\struct {S, \circ, \preceq}$ to itself is a mapping $\phi: S \to S$ that is both:
- $(1): \quad$ A semigroup automorphism, that is, a semigroup isomorphism from the semigroup $\struct {S, \circ}$ to itself
- $(2): \quad$ An order isomorphism from the ordered set $\struct {S, \preceq}$ to itself.
Ordered Group Automorphism
Let $\left({G, \circ, \preceq}\right)$ be an ordered group.
An ordered group automorphism from $\left({G, \circ, \preceq}\right)$ to itself is a mapping $\phi: G \to G$ that is both:
- $(1): \quad$ A group automorphism, that is, a group isomorphism from the group $\left({G, \circ}\right)$ to itself
- $(2): \quad$ An order isomorphism from the ordered set $\left({G, \preceq}\right)$ to itself.
Ordered Ring Automorphism
Let $\struct {R, +, \circ, \preceq}$ be an ordered ring.
An ordered ring automorphism from $\struct {R, +, \circ, \preceq}$ to itself is a mapping $\phi: R \to R$ that is both:
- $(1): \quad$ An ordered group automorphism from the ordered group $\struct {R, +, \preceq}$ to itself
- $(2): \quad$ A semigroup automorphism from the semigroup $\struct {R, \circ}$ to itself.
Also see
Linguistic Note
The word automorphism derives from the Greek morphe (μορφή) meaning form or structure, with the prefix iso- meaning equal.
Thus automorphism means self structure.