Tianyu Zhang

The Following definitions are from the book Measure Theory, by Paul R. Halmos. Aside from the basic definitions, these definitions have tiny size so there will be no attached files associated with the following contents, however, one may find the pdf version by clicking the address short after this intro section.

### 1. Ring

#### Definition

#### Reference

Measure Theory, Paul R. Halmos, Chapter 2 Section 7

#### Related Topics

- Definitions
- Theorems/Corollary/Propositions/Lemmas

### 2. Sigma-Ring

#### Definition

#### Remark

#### Reference

https://en.wikipedia.org/wiki/Sigma-ring

#### Related Topics

- Definitions
- Theorems/Corollary/Propositions/Lemmas

### 3. Delta-Ring

#### Definition

#### Remark

#### Reference

https://en.wikipedia.org/wiki/Delta-ring

#### Related Topics

- Definitions
- Theorems/Corollary/Propositions/Lemmas

### 4. Hereditary Sigma-Ring

#### Definition

#### Remark

#### Reference

Measure Theory, Paul R. Halmos, Chapter 2 Section 10

#### Related Topics

- Definitions
- Theorems/Corollary/Propositions/Lemmas