In mathematics and physics (and other fields of science), it is quite common to use symbols in lieu of names. For instance an object can have a symmetry G, i.e. the name of the symmetry is G.
I am wondering what are the rules for hyphenation when using the adjective version. Does one say that an object is G-symmetric or G symmetric?
In scientific papers, I've seen versions with and without hyphens, sometimes in the same document.
I would expect that the rule should be as for any compound adjective, i.e. hyphenated if attributive and not if predicative. However, to my non-native eyes, saying "this object is G symmetric" doesn't look correct. Is there any rule or at least partial consensus on this?