Redirect to:

This page is a redirect. The following categories are used to track and monitor this redirect:

To an embedded anchor: This is a redirect from a topic that does not have its own page to an embedded anchor on the redirect's target page.
- An {{anchor|anchor name}} or {{visible anchor}} template, an HTML element with id="anchor name", or an |id=anchor name parameter can be placed at the beginning of a paragraph, substituted into a section header, or inserted within a table. Anchors may also be old section headers that have since been renamed, in order to preserve existing internal and external links.
- Although section headers of the form ==(Header name)== act as anchors by default, with them use {{R to section}} instead.

When appropriate, protection levels are automatically sensed, described and categorized.

Antiparallel vectors