User:Maproom/hemi

From 1975 until 1981, I worked for the Oxford English Dictionary. Much of my work involved tracing the earliest recorded usage of terms – in my case, these were mainly medical and mathematical terms. So, now that I may have accidentally coined two words myself, I record the details here for the benefit of future lexicographers.

The terms are "hemi-hosohedron" and "hemi-dihedron". They are used in the article regular map (graph theory). Here are the details.

• In 2009 or thereabouts, I created some web pages on regular maps. A copy of them is now here. It used the standard terms hosohedron and dihedron for certain trivial regular maps in the sphere. When I created the page which listed their analogues in the projective plane, I assumed that they must be called the hemi-hosohedron and the hemi-dihedron, by analogy with the established terms hemicube, hemi-octahedron, hemi-dodecahedron, hemi-icosahedron, hemicuboctahedron, etc. I used these terms, unhyphenated, in the page now archived here.

• In 2011 I made a new version of those web pages. The new page for the projective plane here uses the same terminology, but for specific cases: it lists the hemi-2-hosohedron, the hemi-di-square, the hemi-4-hosohedron, the hemi-di-hexagon, etc.

• In 2013, I noticed that Wikipedia's article regular map (graph theory) listed regular maps in the projective plane, but did not name them. I added the names hemidihedron, hemihosohedron, hemicube, hemioctahedron, hemidodecahedron, hemi-icosahedron, hyphenated thus, with this edit. The Wikipedia article was subsequently mirrored and otherwise copied.

• In January 2015, another editor deleted the names hemidihedron and hemihosohedron from that article, as unreferenced. I searched for references, and found my own web pages, and various copies of the Wikipedia article. But I also found the hyphenated forms "hemi-hosohedron" and "hemi-dihedron" used in a 2013 paper by Carlo H. Séquin.^[1] Citing this as a reference, I restored the terms to the article.

I later noticed that this paper by Professor Séquin cites the 2009 version of my web pages on regular maps. So, while he may, like me, have considered the terms obvious, he may have adopted them from my page on regular maps in the projective plane.