link

5reg

link

A knot/link packet

Content Model
    link ::= (&xml-crossings;, &xml-connections;, &xml-components;,
              &xml-tag;*,
              &packetsyn1;
              &packetsyn2;
              &packetsyn3;
              &packetsyn4;
              &packetsyn5;*)
Attributes
Name | Type
&packetattrlist2col;

&eltaddedver;7.0

## Description

This represents a knot/link packet, one of the many types of packet that together form the packet tree that a user sees when they open a ®ina; data file.

A knot/link packet stores the diagram of an oriented link in 3-dimensional space. Whereas &xml-spatiallink; stores purely geometric data (encoding specific paths through 3-space), this knot/link packet stores purely combinatorial data (encoding the combinatorics of a link diagram).

The number of crossings in the diagram and the signs of these crossings are stored in the child &xml-crossings; element, and the connections between these crossings are stored in the child &xml-connections; element. The child &xml-components; element stores a starting point for each component of the link.

&packetchilddesc;

### Parents

&packetparents;

### Children

The following elements occur in `link`, and are specific to the knot/link packet type:

- &xml-components;
- &xml-connections;
- &xml-crossings;

. &packetchildren;

## Attributes

&packetattrdesc;

## Example

The following &xml; snippet represents the Whitehead link.

    <link label="Whitehead link">
    <crossings size="5">
    - - + + -
    </crossings>
    <connections>
    _1 ^1
    _2 ^4
    _4 ^3
    _0 ^2
    _3 ^0
    </connections>
    <components size="2">
    ^0 _0
    </components>
    </link>