I am a mathematics professor and not a professional editor. But a mathematics manuscript has come to me for editing.
I see clearly that the phrase "C semigroup" needs an hyphen and I have inserted it. (Here C is some adjective denoting a special kind of semigroup).
But I don't know how to hyphenate "C contraction semigroup". Here the noun contraction seem to be working as an adjective.
I would be grateful to any sound suggestion.