The language predeclares the two types:
TEXT <: REFANY MUTEX <: ROOTwhich represent text strings and mutual exclusion semaphores, respectively. These are opaque types. Their properties are specified in the required interfaces Text and Thread.
m3-request@src.dec.com
Last modified on Wed Apr 3 09:39:11 PST 1996 by heydon modified on Mon Apr 18 14:01:18 PDT 1994 by kalsow