WARNING: The numerical PlanetMath entry IDs used as the id values for this template do not work any more, on the PlanetMath side. The template originally used the numerical IDs to produce links such as

http://planetmath.org/?op=getobj&from=objects&id=$ID.

PlanetMath currently redirects such links to its home page instead of finding the intended article. The reason for this are changes at the "planetmath.org" site during year 2018.

Note that this template survived a merge and deletion proposal earlier during year 2016: Wikipedia:Templates_for_discussion/Log/2016_September_20#Template:PlanetMath. A similar Template:PlanetMath still works but see the old discussion about objections.