diff --git a/bootstrap/unix-44/OPB.c b/bootstrap/unix-44/OPB.c
index d099cad7..0b88b1ea 100644
--- a/bootstrap/unix-44/OPB.c
+++ b/bootstrap/unix-44/OPB.c
@@ -1879,7 +1879,7 @@ void OPB_StPar0 (OPT_Node *par0, int16 fctno)
 		case 15: case 16: 
 			if (OPB_NotVar(x)) {
 				OPB_err(112);
-			} else if (x->typ != OPT_settyp) {
+			} else if (x->typ->form != 7) {
 				OPB_err(111);
 				x->typ = OPT_settyp;
 			} else if (x->readonly) {
@@ -2044,7 +2044,7 @@ void OPB_StPar1 (OPT_Node *par0, OPT_Node x, int8 fctno)
 			if (x->class == 8 || x->class == 9) {
 				OPB_err(126);
 			} else if (f == 4) {
-				if ((x->class == 7 && (0 > x->conval->intval || x->conval->intval > (int64)OPM_MaxSet))) {
+				if ((x->class == 7 && (0 > x->conval->intval || x->conval->intval >= (int64)__ASHL(p->typ->size, 3)))) {
 					OPB_err(202);
 				}
 				p = NewOp__54(19, fctno, p, x);
diff --git a/bootstrap/unix-44/OPM.c b/bootstrap/unix-44/OPM.c
index 1457a09c..1ef195b4 100644
--- a/bootstrap/unix-44/OPM.c
+++ b/bootstrap/unix-44/OPM.c
@@ -82,7 +82,6 @@ export int64 OPM_SymRInt64 (void);
 export void OPM_SymRLReal (LONGREAL *lr);
 export void OPM_SymRReal (REAL *r);
 export void OPM_SymRSet (uint32 *s);
-export void OPM_SymRSet64 (uint64 *s);
 export void OPM_SymWCh (CHAR ch);
 export void OPM_SymWInt (int64 i);
 export void OPM_SymWLReal (LONGREAL lr);
@@ -759,11 +758,6 @@ int64 OPM_SymRInt64 (void)
 	return _o_result;
 }
 
-void OPM_SymRSet64 (uint64 *s)
-{
-	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 8);
-}
-
 void OPM_SymRSet (uint32 *s)
 {
 	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 4);
diff --git a/bootstrap/unix-44/OPM.h b/bootstrap/unix-44/OPM.h
index 12db4754..dd3c0c27 100644
--- a/bootstrap/unix-44/OPM.h
+++ b/bootstrap/unix-44/OPM.h
@@ -50,7 +50,6 @@ import int64 OPM_SymRInt64 (void);
 import void OPM_SymRLReal (LONGREAL *lr);
 import void OPM_SymRReal (REAL *r);
 import void OPM_SymRSet (uint32 *s);
-import void OPM_SymRSet64 (uint64 *s);
 import void OPM_SymWCh (CHAR ch);
 import void OPM_SymWInt (int64 i);
 import void OPM_SymWLReal (LONGREAL lr);
diff --git a/bootstrap/unix-48/OPB.c b/bootstrap/unix-48/OPB.c
index d099cad7..0b88b1ea 100644
--- a/bootstrap/unix-48/OPB.c
+++ b/bootstrap/unix-48/OPB.c
@@ -1879,7 +1879,7 @@ void OPB_StPar0 (OPT_Node *par0, int16 fctno)
 		case 15: case 16: 
 			if (OPB_NotVar(x)) {
 				OPB_err(112);
-			} else if (x->typ != OPT_settyp) {
+			} else if (x->typ->form != 7) {
 				OPB_err(111);
 				x->typ = OPT_settyp;
 			} else if (x->readonly) {
@@ -2044,7 +2044,7 @@ void OPB_StPar1 (OPT_Node *par0, OPT_Node x, int8 fctno)
 			if (x->class == 8 || x->class == 9) {
 				OPB_err(126);
 			} else if (f == 4) {
-				if ((x->class == 7 && (0 > x->conval->intval || x->conval->intval > (int64)OPM_MaxSet))) {
+				if ((x->class == 7 && (0 > x->conval->intval || x->conval->intval >= (int64)__ASHL(p->typ->size, 3)))) {
 					OPB_err(202);
 				}
 				p = NewOp__54(19, fctno, p, x);
diff --git a/bootstrap/unix-48/OPM.c b/bootstrap/unix-48/OPM.c
index 1457a09c..1ef195b4 100644
--- a/bootstrap/unix-48/OPM.c
+++ b/bootstrap/unix-48/OPM.c
@@ -82,7 +82,6 @@ export int64 OPM_SymRInt64 (void);
 export void OPM_SymRLReal (LONGREAL *lr);
 export void OPM_SymRReal (REAL *r);
 export void OPM_SymRSet (uint32 *s);
-export void OPM_SymRSet64 (uint64 *s);
 export void OPM_SymWCh (CHAR ch);
 export void OPM_SymWInt (int64 i);
 export void OPM_SymWLReal (LONGREAL lr);
@@ -759,11 +758,6 @@ int64 OPM_SymRInt64 (void)
 	return _o_result;
 }
 
-void OPM_SymRSet64 (uint64 *s)
-{
-	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 8);
-}
-
 void OPM_SymRSet (uint32 *s)
 {
 	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 4);
diff --git a/bootstrap/unix-48/OPM.h b/bootstrap/unix-48/OPM.h
index 12db4754..dd3c0c27 100644
--- a/bootstrap/unix-48/OPM.h
+++ b/bootstrap/unix-48/OPM.h
@@ -50,7 +50,6 @@ import int64 OPM_SymRInt64 (void);
 import void OPM_SymRLReal (LONGREAL *lr);
 import void OPM_SymRReal (REAL *r);
 import void OPM_SymRSet (uint32 *s);
-import void OPM_SymRSet64 (uint64 *s);
 import void OPM_SymWCh (CHAR ch);
 import void OPM_SymWInt (int64 i);
 import void OPM_SymWLReal (LONGREAL lr);
diff --git a/bootstrap/unix-88/OPB.c b/bootstrap/unix-88/OPB.c
index d099cad7..0b88b1ea 100644
--- a/bootstrap/unix-88/OPB.c
+++ b/bootstrap/unix-88/OPB.c
@@ -1879,7 +1879,7 @@ void OPB_StPar0 (OPT_Node *par0, int16 fctno)
 		case 15: case 16: 
 			if (OPB_NotVar(x)) {
 				OPB_err(112);
-			} else if (x->typ != OPT_settyp) {
+			} else if (x->typ->form != 7) {
 				OPB_err(111);
 				x->typ = OPT_settyp;
 			} else if (x->readonly) {
@@ -2044,7 +2044,7 @@ void OPB_StPar1 (OPT_Node *par0, OPT_Node x, int8 fctno)
 			if (x->class == 8 || x->class == 9) {
 				OPB_err(126);
 			} else if (f == 4) {
-				if ((x->class == 7 && (0 > x->conval->intval || x->conval->intval > (int64)OPM_MaxSet))) {
+				if ((x->class == 7 && (0 > x->conval->intval || x->conval->intval >= (int64)__ASHL(p->typ->size, 3)))) {
 					OPB_err(202);
 				}
 				p = NewOp__54(19, fctno, p, x);
diff --git a/bootstrap/unix-88/OPM.c b/bootstrap/unix-88/OPM.c
index 0c2ad2b1..41d574f6 100644
--- a/bootstrap/unix-88/OPM.c
+++ b/bootstrap/unix-88/OPM.c
@@ -82,7 +82,6 @@ export int64 OPM_SymRInt64 (void);
 export void OPM_SymRLReal (LONGREAL *lr);
 export void OPM_SymRReal (REAL *r);
 export void OPM_SymRSet (uint32 *s);
-export void OPM_SymRSet64 (uint64 *s);
 export void OPM_SymWCh (CHAR ch);
 export void OPM_SymWInt (int64 i);
 export void OPM_SymWLReal (LONGREAL lr);
@@ -759,11 +758,6 @@ int64 OPM_SymRInt64 (void)
 	return _o_result;
 }
 
-void OPM_SymRSet64 (uint64 *s)
-{
-	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 8);
-}
-
 void OPM_SymRSet (uint32 *s)
 {
 	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 4);
diff --git a/bootstrap/unix-88/OPM.h b/bootstrap/unix-88/OPM.h
index 12db4754..dd3c0c27 100644
--- a/bootstrap/unix-88/OPM.h
+++ b/bootstrap/unix-88/OPM.h
@@ -50,7 +50,6 @@ import int64 OPM_SymRInt64 (void);
 import void OPM_SymRLReal (LONGREAL *lr);
 import void OPM_SymRReal (REAL *r);
 import void OPM_SymRSet (uint32 *s);
-import void OPM_SymRSet64 (uint64 *s);
 import void OPM_SymWCh (CHAR ch);
 import void OPM_SymWInt (int64 i);
 import void OPM_SymWLReal (LONGREAL lr);
diff --git a/bootstrap/windows-48/OPB.c b/bootstrap/windows-48/OPB.c
index d099cad7..0b88b1ea 100644
--- a/bootstrap/windows-48/OPB.c
+++ b/bootstrap/windows-48/OPB.c
@@ -1879,7 +1879,7 @@ void OPB_StPar0 (OPT_Node *par0, int16 fctno)
 		case 15: case 16: 
 			if (OPB_NotVar(x)) {
 				OPB_err(112);
-			} else if (x->typ != OPT_settyp) {
+			} else if (x->typ->form != 7) {
 				OPB_err(111);
 				x->typ = OPT_settyp;
 			} else if (x->readonly) {
@@ -2044,7 +2044,7 @@ void OPB_StPar1 (OPT_Node *par0, OPT_Node x, int8 fctno)
 			if (x->class == 8 || x->class == 9) {
 				OPB_err(126);
 			} else if (f == 4) {
-				if ((x->class == 7 && (0 > x->conval->intval || x->conval->intval > (int64)OPM_MaxSet))) {
+				if ((x->class == 7 && (0 > x->conval->intval || x->conval->intval >= (int64)__ASHL(p->typ->size, 3)))) {
 					OPB_err(202);
 				}
 				p = NewOp__54(19, fctno, p, x);
diff --git a/bootstrap/windows-48/OPM.c b/bootstrap/windows-48/OPM.c
index 1457a09c..1ef195b4 100644
--- a/bootstrap/windows-48/OPM.c
+++ b/bootstrap/windows-48/OPM.c
@@ -82,7 +82,6 @@ export int64 OPM_SymRInt64 (void);
 export void OPM_SymRLReal (LONGREAL *lr);
 export void OPM_SymRReal (REAL *r);
 export void OPM_SymRSet (uint32 *s);
-export void OPM_SymRSet64 (uint64 *s);
 export void OPM_SymWCh (CHAR ch);
 export void OPM_SymWInt (int64 i);
 export void OPM_SymWLReal (LONGREAL lr);
@@ -759,11 +758,6 @@ int64 OPM_SymRInt64 (void)
 	return _o_result;
 }
 
-void OPM_SymRSet64 (uint64 *s)
-{
-	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 8);
-}
-
 void OPM_SymRSet (uint32 *s)
 {
 	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 4);
diff --git a/bootstrap/windows-48/OPM.h b/bootstrap/windows-48/OPM.h
index 12db4754..dd3c0c27 100644
--- a/bootstrap/windows-48/OPM.h
+++ b/bootstrap/windows-48/OPM.h
@@ -50,7 +50,6 @@ import int64 OPM_SymRInt64 (void);
 import void OPM_SymRLReal (LONGREAL *lr);
 import void OPM_SymRReal (REAL *r);
 import void OPM_SymRSet (uint32 *s);
-import void OPM_SymRSet64 (uint64 *s);
 import void OPM_SymWCh (CHAR ch);
 import void OPM_SymWInt (int64 i);
 import void OPM_SymWLReal (LONGREAL lr);
diff --git a/bootstrap/windows-88/OPB.c b/bootstrap/windows-88/OPB.c
index d099cad7..0b88b1ea 100644
--- a/bootstrap/windows-88/OPB.c
+++ b/bootstrap/windows-88/OPB.c
@@ -1879,7 +1879,7 @@ void OPB_StPar0 (OPT_Node *par0, int16 fctno)
 		case 15: case 16: 
 			if (OPB_NotVar(x)) {
 				OPB_err(112);
-			} else if (x->typ != OPT_settyp) {
+			} else if (x->typ->form != 7) {
 				OPB_err(111);
 				x->typ = OPT_settyp;
 			} else if (x->readonly) {
@@ -2044,7 +2044,7 @@ void OPB_StPar1 (OPT_Node *par0, OPT_Node x, int8 fctno)
 			if (x->class == 8 || x->class == 9) {
 				OPB_err(126);
 			} else if (f == 4) {
-				if ((x->class == 7 && (0 > x->conval->intval || x->conval->intval > (int64)OPM_MaxSet))) {
+				if ((x->class == 7 && (0 > x->conval->intval || x->conval->intval >= (int64)__ASHL(p->typ->size, 3)))) {
 					OPB_err(202);
 				}
 				p = NewOp__54(19, fctno, p, x);
diff --git a/bootstrap/windows-88/OPM.c b/bootstrap/windows-88/OPM.c
index 0c2ad2b1..41d574f6 100644
--- a/bootstrap/windows-88/OPM.c
+++ b/bootstrap/windows-88/OPM.c
@@ -82,7 +82,6 @@ export int64 OPM_SymRInt64 (void);
 export void OPM_SymRLReal (LONGREAL *lr);
 export void OPM_SymRReal (REAL *r);
 export void OPM_SymRSet (uint32 *s);
-export void OPM_SymRSet64 (uint64 *s);
 export void OPM_SymWCh (CHAR ch);
 export void OPM_SymWInt (int64 i);
 export void OPM_SymWLReal (LONGREAL lr);
@@ -759,11 +758,6 @@ int64 OPM_SymRInt64 (void)
 	return _o_result;
 }
 
-void OPM_SymRSet64 (uint64 *s)
-{
-	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 8);
-}
-
 void OPM_SymRSet (uint32 *s)
 {
 	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 4);
diff --git a/bootstrap/windows-88/OPM.h b/bootstrap/windows-88/OPM.h
index 12db4754..dd3c0c27 100644
--- a/bootstrap/windows-88/OPM.h
+++ b/bootstrap/windows-88/OPM.h
@@ -50,7 +50,6 @@ import int64 OPM_SymRInt64 (void);
 import void OPM_SymRLReal (LONGREAL *lr);
 import void OPM_SymRReal (REAL *r);
 import void OPM_SymRSet (uint32 *s);
-import void OPM_SymRSet64 (uint64 *s);
 import void OPM_SymWCh (CHAR ch);
 import void OPM_SymWInt (int64 i);
 import void OPM_SymWLReal (LONGREAL lr);
diff --git a/src/compiler/OPB.Mod b/src/compiler/OPB.Mod
index b29f6b49..c1a317d2 100644
--- a/src/compiler/OPB.Mod
+++ b/src/compiler/OPB.Mod
@@ -811,11 +811,11 @@ MODULE OPB;  (* RC 6.3.89 / 21.2.94 *)  (* object model 17.1.93 *)
         ELSE err(201); x^.conval^.setval := {l..k}
         END ;
         x^.obj := NIL
-      ELSE BindNodes(OPT.Nupto, OPT.settyp, x, y)
+      ELSE BindNodes(OPT.Nupto, OPT.settyp, x, y) (* todo choose appropriate set type ? *)
       END
     ELSE err(93)
     END ;
-    x^.typ := OPT.settyp
+    x^.typ := OPT.settyp (* todo choose appropriate set type ? *)
   END SetRange;
 
   PROCEDURE SetElem*(VAR x: OPT.Node);
@@ -829,9 +829,9 @@ MODULE OPB;  (* RC 6.3.89 / 21.2.94 *)  (* object model 17.1.93 *)
       ELSE err(202)
       END ;
       x^.obj := NIL
-    ELSE Convert(x, OPT.settyp)
+    ELSE Convert(x, OPT.settyp)  (* todo choose appropriate set type ? *)
     END ;
-    x^.typ := OPT.settyp
+    x^.typ := OPT.settyp  (* todo choose appropriate set type ? *)
   END SetElem;
 
   PROCEDURE CheckAssign(x: OPT.Struct; ynode: OPT.Node);  (* x := y *)
@@ -1027,7 +1027,7 @@ MODULE OPB;  (* RC 6.3.89 / 21.2.94 *)  (* object model 17.1.93 *)
     |OPT.inclfn,
      OPT.exclfn:   (*INCL, EXCL*)
                    IF NotVar(x) THEN err(112)
-                   ELSIF x^.typ # OPT.settyp THEN err(111); x^.typ := OPT.settyp
+                   ELSIF x.typ.form # OPT.Set THEN err(111); x^.typ := OPT.settyp
                    ELSIF x^.readonly THEN err(76)
                    END
     |OPT.lenfn:    (*LEN*)
@@ -1124,8 +1124,8 @@ MODULE OPB;  (* RC 6.3.89 / 21.2.94 *)  (* object model 17.1.93 *)
      OPT.exclfn:   (*INCL, EXCL*)
                    IF (x^.class = OPT.Ntype) OR (x^.class = OPT.Nproc) THEN err(126)
                    ELSIF f = OPT.Int THEN
-                     IF (x^.class = OPT.Nconst) & ((0 > x^.conval^.intval) OR (x^.conval^.intval > OPM.MaxSet)) THEN err(202)
-                     END ;
+                     IF (x^.class = OPT.Nconst) & ((0 > x^.conval^.intval) OR (x^.conval^.intval >= p.typ.size*8)) THEN err(202)
+                     END;
                      p := NewOp(OPT.Nassign, fctno, p, x)
                    ELSE err(111)
                    END ;
diff --git a/src/compiler/OPM.Mod b/src/compiler/OPM.Mod
index a2beb450..a18953a7 100644
--- a/src/compiler/OPM.Mod
+++ b/src/compiler/OPM.Mod
@@ -552,7 +552,7 @@ MODULE OPM;  (* RC 6.3.89 / 28.6.89, J.Templ 10.7.89 / 22.7.96  *)
   END FPrint;
 
 
-  PROCEDURE FPrintSet*(VAR fp: LONGINT; set: SET);
+  PROCEDURE FPrintSet*(VAR fp: LONGINT; set: SET); (*SYSTEM.SET64);*)
   BEGIN FPrint(fp, SYSTEM.VAL(LONGINT, set))
   END FPrintSet;
 
@@ -603,12 +603,7 @@ MODULE OPM;  (* RC 6.3.89 / 28.6.89, J.Templ 10.7.89 / 22.7.96  *)
   BEGIN Files.ReadNum(oldSF, k); RETURN k
   END SymRInt64;
 
-  (* todo - combine RSet64 and RSet *)
-  PROCEDURE SymRSet64*(VAR s: SYSTEM.SET64);
-  BEGIN Files.ReadNum(oldSF, s)
-  END SymRSet64;
-
-  PROCEDURE SymRSet*(VAR s: SET);
+  PROCEDURE SymRSet*(VAR s: SET); (*SYSTEM.SET64);*)
   BEGIN Files.ReadNum(oldSF, s)
   END SymRSet;
 
@@ -653,7 +648,7 @@ MODULE OPM;  (* RC 6.3.89 / 28.6.89, J.Templ 10.7.89 / 22.7.96  *)
   BEGIN Files.WriteNum(newSF, i)
   END SymWInt;
 
-  (* todo
+  (*
   PROCEDURE SymWSet*(s: SYSTEM.SET64);
   BEGIN Files.WriteNum(newSF, SYSTEM.VAL(SYSTEM.INT64, s))
   END SymWSet;
diff --git a/src/compiler/OPT.Mod b/src/compiler/OPT.Mod
index e55c7d3c..a3960ac2 100644
--- a/src/compiler/OPT.Mod
+++ b/src/compiler/OPT.Mod
@@ -15,10 +15,8 @@ TYPE
     ext*:      ConstExt;      (* string or code for code proc *)
     intval*:   SYSTEM.INT64;  (* constant value or adr, proc par size, text position or least case label *)
     intval2*:  LONGINT;       (* string length, proc var size or larger case label *)
-    (* todo
-    setval*:   SYSTEM.SET64;  (* constant value, procedure body present or "ELSE" present in case *)
-    *)
-    setval*:   SET;           (* constant value, procedure body present or "ELSE" present in case *)
+  (*setval*:   SYSTEM.SET64;*)  (* constant value, procedure body present or "ELSE" present in case *)
+    setval*:   SET;  (* constant value, procedure body present or "ELSE" present in case *)
     realval*:  LONGREAL       (* real or longreal constant value *)
   END;