# CDR 5: Extra Numerical Types for Common Lisp

## Note

This is an old version of this document, and is kept only for archival purposes. Please refer to the most current version of this document.

## Author / Submitter

Marco Antoniotti

## Abstract / Rationale

When working on numerical algorithms it is sometimes useful to further
constrain the types of certain values to sub-intervals of the usual
types present in Common Lisp. A typical example is that of indices
running over the dimensions of an array: such integers values should
not be negative. While several Common Lisp implementations already
have certain special "sub-interval" type specifiers that can be used
in implementation dependent code, it seems natural and relatively
uncontroversial to propose a set of specialized types that codify
usual mathematical numerical sets and intervals. This document puts
forward such a proposal.

## The Document

## Status

Superseded

CDR - Common Lisp Document Repository

The CDR Editors

This page last modified: April 12, 2008