Definition:Subfield/Ring

Definition

Let $\struct {R, +, \circ}$ be a ring with unity.

Let $K$ be a subset of $R$ such that $\struct {K, +, \circ}$ is a field.

Then $\struct {K, +, \circ}$ is a subfield of $\struct {R, +, \circ}$.

Also see

• Results about subfields can be found here.

Sources

• 1964: Iain T. Adamson: Introduction to Field Theory ... (previous) ... (next): Chapter $\text {I}$: Elementary Definitions: $\S 2$. Elementary Properties