Do I need to to hyphenate:

"It is a locally-injective mapping."

where I use locally injective as a term--a concept:

"This mapping is locally injective."

For example, it is defined in:

[Weber14 "Locally Injective Parametrization with Arbitrary Fixed Boundaries"]


Adding some links regarding hyphenating the adverb 'well', which may be relevant:

A Well-Known Problem: Hyphens With “Well” Words https://www.businesswritingblog.com/business_writing/2009/07/a-wellknown-problem-well-known.html

Well-Hyphenated Compound Adjectives https://www.btb.termiumplus.gc.ca/tpv2guides/guides/favart/index-fra.html?lang=fra&lettr=indx_autr8O0GT3FD1GuY&page=9p1twFAGORMI.html

"The elements of style" by Strunk and White says:

"When two or more words are combined to form a compound adjective, a hyphen is usually required."

The wiki page is quite comprehensive and sounds convincing:


  • Welcome to EL&U. Please give the definition in context in your question; an excerpt from that link perhaps would be helpful. – livresque Oct 1 '20 at 23:30
  • Since locally is an adverb, people will assume that it is modifying the following adjective, injective. No hyphen is needed. – Peter Shor Oct 2 '20 at 0:03

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