+ | LBRACK typ RBRACK (TList typ, (LBRACKleft, RBRACKright))
+ | typ ARROW typ (TArrow (typ1, typ2), (typleft, typright))
+ | LBRACK ctxt RBRACK recd DARROW recd (TAction (ctxt, recd1, recd2), (LBRACKleft, recd2right))
+ | LBRACK ctxt RBRACK recd (TAction (ctxt, recd, StringMap.empty),
+ (LBRACKleft, recdright))
+ | LBRACK ctxt RBRACK (TAction (ctxt, StringMap.empty, StringMap.empty),
+ (LBRACKleft, ctxtright))
+ | LPAREN typ RPAREN (typ)
+ | ctxt DARROW typ (TNested (ctxt, typ), (ctxtleft, typright))
+
+recd : LBRACE RBRACE (StringMap.empty)
+ | LBRACE recdNe RBRACE (recdNe)
+
+recdNe : CSYMBOL COLON typ (StringMap.insert (StringMap.empty, CSYMBOL, typ))
+ | CSYMBOL COLON typ COMMA recdNe (StringMap.insert (recdNe, CSYMBOL, typ))
+
+ctxt : ROOT (CRoot, (ROOTleft, ROOTright))
+ | CSYMBOL (CConst CSYMBOL, (CSYMBOLleft, CSYMBOLright))
+ | CARET ctxt (CPrefix ctxt, (CARETleft, ctxtright))
+ | BANG ctxt (CNot ctxt, (BANGleft, ctxtright))
+ | ctxt AND ctxt (CAnd (ctxt1, ctxt2), (ctxt1left, ctxt2right))
+ | LPAREN ctxt RPAREN (ctxt)