+
+and context_entry = (* A declaration or definition *)
+ Decl of term
+ | Def of term
+
+and hypothesis =
+ (name * context_entry) option (* None means no more accessible *)
+
+and context = hypothesis list
+
+and anncontext_entry = (* A declaration or definition *)
+ ADecl of annterm
+ | ADef of annterm
+
+and annhypothesis =
+ id * (name * anncontext_entry) option (* None means no more accessible *)
+
+and anncontext = annhypothesis list;;