alias MuglueParameter

---

(alias) MuglueParameter = ("medmuskip"|"thickmuskip"|"thinmuskip")
    | "medmuskip" -- Medium amount of mu (math units) glue.
    | "thickmuskip" -- Large amount of mu (math units) glue.
    | "thinmuskip" -- Small amount of mu (math units) glue.

All muglue (math units) parameters are to be used read-only and return a Lua string.

Reference:

• Source file of the LuaTeX manual: luatex-tex.tex#L503-505