# Definition:Order Type of Real Numbers/Historical Note

Jump to navigation
Jump to search

## Historical Note on Order Type of Real Numbers

The use of $\lambda$ to denote the **order type of $\struct {\R, \le}$** dates back to the writings of Georg Cantor and Felix Hausdorff.

According to Winfried Just and Martin Weese in their *Discovering Modern Set Theory. I: The Basics* of $1996$, this order type, along with that for $\struct {\Q, \le}$, has not been greatly studied in recent years.

$\lambda$ is in fact far more often used to denote an infinite cardinal.

## Sources

- 1996: Winfried Just and Martin Weese:
*Discovering Modern Set Theory. I: The Basics*... (previous) ... (next): Part $1$: Not Entirely Naive Set Theory: Chapter $2$: Partial Order Relations: Mathographical Remarks