diff --git a/samples/bank.as b/samples/bank.as
index 9d475d2568f..ace922cc10e 100644
--- a/samples/bank.as
+++ b/samples/bank.as
@@ -13,7 +13,7 @@ actor class Issuer() {
   };
 };
 
-actor class Account(initialBalance : Int) {
+actor class Account(initialBalance : Int) = this {
   private var balance : Int = initialBalance;
 
   getBalance() : async Int {
@@ -25,15 +25,15 @@ actor class Account(initialBalance : Int) {
     return Account(amount);
   };
 
-  join(account : Account) {  // this implicitly asserts that account is Account
+  join(account : like Account) {
+    assert(account is Account);
     let amount = balance;
     balance := 0;
-    account.credit(amount);
+    account.credit(amount, Account);
   };
 
-  private credit(amount : Int) {
-    // private implicitly asserts that caller is own class
-    // by implicitly passing the modref as an extra argument
+  credit(amount : Int, caller : Class) {
+    assert(this is caller);
     balance += amount;
   };
 
diff --git a/samples/bank.txt b/samples/bank.txt
index 5d6976f5394..c943e400f99 100644
--- a/samples/bank.txt
+++ b/samples/bank.txt
@@ -1,5 +1,5 @@
 -- Checking bank.as:
-type Account <: actor {getBalance : shared () -> async Int; isCompatible : shared (like Account) -> async Bool; join : shared Account -> (); split : shared Int -> async Account}
+type Account <: actor {credit : shared (Int, Class) -> (); getBalance : shared () -> async Int; isCompatible : shared (like Account) -> async Bool; join : shared (like Account) -> (); split : shared Int -> async Account}
 type Bank <: actor {getIssuer : shared () -> async Issuer; getReserve : shared () -> async Account}
 type Issuer <: actor {hasIssued : shared (like Account) -> async Bool}
 let Account : class Int -> Account
@@ -15,8 +15,8 @@ Bank(100)
   Issuer()
     <= {hasIssued = func}
   Account(100)
-    <= {balance = 100; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-  <= {getIssuer = func; getReserve = func; issuer = {hasIssued = func}; reserve = {balance = 100; credit = func; getBalance = func; isCompatible = func; join = func; split = func}}
+    <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+  <= {getIssuer = func; getReserve = func}
 test()
   -> async bank.as:56.40-68.2
   <= async _
@@ -28,8 +28,8 @@ test()
     -> async bank.as:7.32-7.51
     <= async _
 <- async bank.as:7.32-7.51
-  <= {balance = 100; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-<- await bank.as:57.17-57.40({balance = 100; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+<- await bank.as:57.17-57.40({credit = func; getBalance = func; isCompatible = func; join = func; split = func})
   -> message split(10)
   => await bank.as:58.12-58.35
 <- message split(10)
@@ -38,9 +38,9 @@ test()
     <= async _
 <- async bank.as:23.39-26.4
   Account(10)
-    <= {balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-  <= {balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-<- await bank.as:58.12-58.35({balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+    <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+  <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+<- await bank.as:58.12-58.35({credit = func; getBalance = func; isCompatible = func; join = func; split = func})
   -> message split(10)
   => await bank.as:59.12-59.35
 <- message split(10)
@@ -49,16 +49,16 @@ test()
     <= async _
 <- async bank.as:23.39-26.4
   Account(10)
-    <= {balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-  <= {balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-<- await bank.as:59.12-59.35({balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
-  show("reserve", {balance = 80; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+    <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+  <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+<- await bank.as:59.12-59.35({credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  show("reserve", {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
     <= ()
-  show("a1", {balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  show("a1", {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
     <= ()
-  show("a2", {balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  show("a2", {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
     <= ()
-  transfer({balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func}, {balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func}, 5)
+  transfer({credit = func; getBalance = func; isCompatible = func; join = func; split = func}, {credit = func; getBalance = func; isCompatible = func; join = func; split = func}, 5)
     -> async bank.as:46.79-49.2
     <= async _
   => await bank.as:63.3-63.28
@@ -71,30 +71,32 @@ test()
     <= async _
 <- async bank.as:23.39-26.4
   Account(5)
-    <= {balance = 5; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-  <= {balance = 5; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-<- await bank.as:47.13-47.39({balance = 5; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
-  -> message join({balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+    <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+  <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+<- await bank.as:47.13-47.39({credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  -> message join({credit = func; getBalance = func; isCompatible = func; join = func; split = func})
   <= ()
-<- message join({balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
-  join({balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
-    credit(5)
-      <= ()
+<- message join({credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  join({credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+    -> message credit(5, class)
+    <= ()
+<- message credit(5, class)
+  credit(5, class)
     <= ()
 <- await bank.as:63.3-63.28()
-  show("reserve", {balance = 80; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  show("reserve", {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
     <= ()
-  show("a1", {balance = 5; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  show("a1", {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
     <= ()
-  show("a2", {balance = 15; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  show("a2", {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
     <= ()
-  <= ({balance = 5; credit = func; getBalance = func; isCompatible = func; join = func; split = func}, {balance = 15; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  <= ({credit = func; getBalance = func; isCompatible = func; join = func; split = func}, {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
 -- Finished bank.as:
 let Account : class Int -> Account = class
 let Bank : class Int -> Bank = class
 let Issuer : class () -> Issuer = class
-let bank : Bank = {getIssuer = func; getReserve = func; issuer = {hasIssued = func}; reserve = {balance = 80; credit = func; getBalance = func; isCompatible = func; join = func; split = func}}
-let main : async (Account, Account) = async ({balance = 5; credit = func; getBalance = func; isCompatible = func; join = func; split = func}, {balance = 15; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+let bank : Bank = {getIssuer = func; getReserve = func}
+let main : async (Account, Account) = async ({credit = func; getBalance = func; isCompatible = func; join = func; split = func}, {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
 let show : (Text, Account) -> () = func
 let test : () -> async (Account, Account) = func
 let transfer : (Account, Account, Int) -> async () = func
diff --git a/samples/cheque.txt b/samples/cheque.txt
index 87950094b9e..c0ebd18060c 100644
--- a/samples/cheque.txt
+++ b/samples/cheque.txt
@@ -18,8 +18,8 @@ Bank(100)
   Issuer()
     <= {hasIssued = func}
   Account(100)
-    <= {balance = 100; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
-  <= {getIssuer = func; getReserve = func; issuer = {hasIssued = func}; reserve = {balance = 100; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}}
+    <= {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
+  <= {getIssuer = func; getReserve = func}
 test()
   -> async cheque.as:76.39-88.2
   <= async _
@@ -31,8 +31,8 @@ test()
     -> async cheque.as:7.32-7.51
     <= async _
 <- async cheque.as:7.32-7.51
-  <= {balance = 100; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
-<- await cheque.as:77.17-77.40({balance = 100; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  <= {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
+<- await cheque.as:77.17-77.40({credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
   -> message split(10)
   => await cheque.as:78.12-78.35
 <- message split(10)
@@ -41,9 +41,9 @@ test()
     <= async _
 <- async cheque.as:32.39-35.4
   Account(10)
-    <= {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
-  <= {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
-<- await cheque.as:78.12-78.35({balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+    <= {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
+  <= {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
+<- await cheque.as:78.12-78.35({credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
   -> message split(10)
   => await cheque.as:79.12-79.35
 <- message split(10)
@@ -52,35 +52,35 @@ test()
     <= async _
 <- async cheque.as:32.39-35.4
   Account(10)
-    <= {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
-  <= {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
-<- await cheque.as:79.12-79.35({balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
-  show("reserve", {balance = 80; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+    <= {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
+  <= {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
+<- await cheque.as:79.12-79.35({credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  show("reserve", {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
     <= ()
-  show("a1", {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  show("a1", {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
     <= ()
-  show("a2", {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  show("a2", {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
     <= ()
-  transfer({balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, 5)
+  transfer({credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, 5)
     -> async cheque.as:64.79-67.2
     <= async _
   => await cheque.as:83.3-83.28
 <- async cheque.as:64.79-67.2
-  -> message invoice(5, {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  -> message invoice(5, {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
   => await cheque.as:65.16-65.53
-<- message invoice(5, {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
-  invoice(5, {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+<- message invoice(5, {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  invoice(5, {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
     -> async cheque.as:41.59-44.4
     <= async _
 <- async cheque.as:41.59-44.4
-  Cheque(5, {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
-    <= {current = 5; deposit = func}
-  <= {current = 5; deposit = func}
-<- await cheque.as:65.16-65.53({current = 5; deposit = func})
-  -> message deposit({current = 5; deposit = func})
+  Cheque(5, {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+    <= {deposit = func}
+  <= {deposit = func}
+<- await cheque.as:65.16-65.53({deposit = func})
+  -> message deposit({deposit = func})
   <= ()
-<- message deposit({current = 5; deposit = func})
-  deposit({current = 5; deposit = func})
+<- message deposit({deposit = func})
+  deposit({deposit = func})
     -> message deposit()
     <= ()
 <- message deposit()
@@ -91,7 +91,7 @@ test()
   credit(5)
     <= ()
 <- await cheque.as:83.3-83.28()
-  show("reserve", {balance = 80; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  show("reserve", {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
     <= ()
   -> message getBalance()
   => await cheque.as:85.21-85.42
@@ -115,14 +115,14 @@ test()
 <- await cheque.as:86.21-86.42(15)
   showBalance("b2", 15)
     <= ()
-  <= ({balance = 5; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, {balance = 15; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  <= ({credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
 -- Finished cheque.as:
 let Account : class Int -> Account = class
 let Bank : class Int -> Bank = class
 let Cheque : class (Int, Account) -> Cheque = class
 let Issuer : class () -> Issuer = class
-let bank : Bank = {getIssuer = func; getReserve = func; issuer = {hasIssued = func}; reserve = {balance = 80; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}}
-let main : async (Account, Account) = async ({balance = 5; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, {balance = 15; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+let bank : Bank = {getIssuer = func; getReserve = func}
+let main : async (Account, Account) = async ({credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
 let show : (Text, Account) -> () = func
 let showBalance : (Text, Int) -> () = func
 let test : () -> async (Account, Account) = func
diff --git a/samples/counter.txt b/samples/counter.txt
index 47cdd4a8a8c..4df26ec213a 100644
--- a/samples/counter.txt
+++ b/samples/counter.txt
@@ -8,7 +8,7 @@ let testDec : () -> ()
 let testRead : () -> ()
 -- Interpreting counter.as:
 Counter(10)
-  <= {c = 10; dec = func; read = func}
+  <= {dec = func; read = func}
 testDec()
   -> message dec()
   -> message dec()
@@ -288,7 +288,7 @@ testRead()
   <= ()
 -- Finished counter.as:
 let Counter : class Int -> Counter = class
-let c : Counter = {c = -10; dec = func; read = func}
+let c : Counter = {dec = func; read = func}
 let show : (Text, Int) -> () = func
 let showAsync : (Text, async Int) -> () = func
 let testDec : () -> () = func
diff --git a/samples/quicksort.txt b/samples/quicksort.txt
index c7520c795ce..e82cb16c9f9 100644
--- a/samples/quicksort.txt
+++ b/samples/quicksort.txt
@@ -7,7 +7,7 @@ let cmpi : (Int, Int) -> Int
 let qs : QS<Int>
 -- Interpreting quicksort.as:
 QS(func)
-  <= {partition = func; quicksort = func; swap = func; trace = func}
+  <= {quicksort = func}
 quicksort([8, 3, 9, 5, 2], 0, 4)
   partition([8, 3, 9, 5, 2], 0, 4)
     trace([8, 3, 9, 5, 2])
@@ -100,5 +100,5 @@ quicksort([8, 3, 9, 5, 2], 0, 4)
 let QS : class <T>((T, T) -> Int) -> QS<T> = class
 let a : Array<Int> = [2, 3, 5, 8, 9]
 let cmpi : (Int, Int) -> Int = func
-let qs : QS<Int> = {partition = func; quicksort = func; swap = func; trace = func}
+let qs : QS<Int> = {quicksort = func}
 
diff --git a/src/arrange.ml b/src/arrange.ml
index 75be6bcfcf5..ce8cce742c0 100644
--- a/src/arrange.ml
+++ b/src/arrange.ml
@@ -160,7 +160,7 @@ and dec d = match d.it with
     "FuncD" $$ [Atom (sharing s.it); id i] @ List.map typ_bind tp @ [pat p; typ t; exp e]
   | TypD (i, tp, t) ->
     "TypD" $$ [id i] @ List.map typ_bind tp @ [typ t]
-  | ClassD (i, j, tp, s, p, efs) ->
-    "ClassD" $$ id i :: id j :: List.map typ_bind tp @ [obj_sort s; pat p] @ List.map exp_field efs
+  | ClassD (i, j, tp, s, p, i', efs) ->
+    "ClassD" $$ id i :: id j :: List.map typ_bind tp @ [obj_sort s; pat p; id i'] @ List.map exp_field efs
 
 and prog prog = "BlockE"  $$ List.map dec prog.it                                                                       
diff --git a/src/async.ml b/src/async.ml
index ffcbc34d981..1e7f16ede91 100644
--- a/src/async.ml
+++ b/src/async.ml
@@ -406,9 +406,9 @@ and t_dec' dec' =
           | _ -> failwith "async.ml t_dec': funcD3"
          end
     end
-  | ClassD (id, lab, typbinds, sort, pat, fields) ->
+  | ClassD (id, lab, typbinds, sort, pat, id', fields) ->
      let fields' = t_fields fields in             
-     ClassD (id, lab, t_typbinds typbinds, sort, t_pat pat, fields')
+     ClassD (id, lab, t_typbinds typbinds, sort, t_pat pat, id', fields')
 
 and t_decs decs = List.map t_dec decs           
 
diff --git a/src/await.ml b/src/await.ml
index 747993e3927..2430d5aa71d 100644
--- a/src/await.ml
+++ b/src/await.ml
@@ -113,7 +113,7 @@ and infer_effect_dec dec =
     T.Triv
   | FuncD (s, v, tps, p, t, e) ->
     T.Triv
-  | ClassD (v, l, tps, s, p, efs) ->
+  | ClassD (v, l, tps, s, p, v', efs) ->
     T.Triv
 
 (* sugar *)                      
@@ -436,10 +436,10 @@ and t_dec' context dec' =
     let context' = LabelEnv.add id_ret Label LabelEnv.empty in
     FuncD (sh, id, typbinds, pat, typ,t_exp context' exp)
 
-  | ClassD (id, lab, typbinds, sort, pat, fields) ->
+  | ClassD (id, lab, typbinds, sort, pat, id', fields) ->
     let context' = LabelEnv.add id_ret Label LabelEnv.empty in     
     let fields' = t_fields context' fields in             
-    ClassD (id, lab, typbinds, sort, pat, fields')
+    ClassD (id, lab, typbinds, sort, pat, id', fields')
 and t_decs context decs = List.map (t_dec context) decs           
 and t_fields context fields = 
   List.map (fun (field:exp_field) ->
@@ -831,7 +831,7 @@ and c_dec context dec =
                   (k -@- define_idE id Var v)))
      end                                       
   | FuncD  (_, id, _ (* typbinds *), _ (* pat *), _ (* typ *), _ (* exp *) ) 
-  | ClassD (id, _ (* lab *),  _ (* typbinds *), _ (* sort *), _ (* pat *), _ (* fields *) ) ->     
+  | ClassD (id, _ (* lab *),  _ (* typbinds *), _ (* sort *), _ (* pat *), _ (* id *), _ (* fields *) ) ->
      (* todo: use a block not lets as in LetD *)
     let func_typ = typ_dec dec in
     let k = fresh_cont func_typ in
@@ -868,7 +868,7 @@ and declare_dec dec exp : exp =
   | LetD (pat, _) -> declare_pat pat exp
   | VarD (id, exp1) -> declare_id id (T.Mut (typ exp1)) exp
   | FuncD (_, id, _, _, _, _)
-  | ClassD (id, _, _, _, _, _) -> declare_id id (typ_dec dec) exp
+  | ClassD (id, _, _, _, _, _, _) -> declare_id id (typ_dec dec) exp
 
 and declare_decs decs exp : exp =
   match decs with
diff --git a/src/awaitopt.ml b/src/awaitopt.ml
index e5b6d80821e..a63e97d6f99 100644
--- a/src/awaitopt.ml
+++ b/src/awaitopt.ml
@@ -114,7 +114,7 @@ and infer_effect_dec dec =
     T.Triv
   | FuncD (s, v, tps, p, t, e) ->
     T.Triv
-  | ClassD (v, l, tps, s, p, efs) ->
+  | ClassD (v, l, tps, s, p, v', efs) ->
     T.Triv
 
 
@@ -497,10 +497,10 @@ and t_dec' context dec' =
   | FuncD (s, id, typbinds, pat, typ, exp) ->
     let context' = LabelEnv.add id_ret Label LabelEnv.empty in
     FuncD (s, id, typbinds, pat, typ,t_exp context' exp)
-  | ClassD (id, lab, typbinds, sort, pat, fields) ->
+  | ClassD (id, lab, typbinds, sort, pat, id', fields) ->
     let context' = LabelEnv.add id_ret Label LabelEnv.empty in     
     let fields' = t_fields context' fields in             
-    ClassD (id, lab, typbinds, sort, pat, fields')
+    ClassD (id, lab, typbinds, sort, pat, id', fields')
 
 and t_decs context decs = List.map (t_dec context) decs           
 
@@ -880,7 +880,7 @@ and c_dec context dec (k:kont) =
              (fun v -> k -@- define_idE id Var v))
      end                                       
   | FuncD  (_, id, _ (* typbinds *), _ (* pat *), _ (* typ *), _ (* exp *) ) 
-  | ClassD (id, _ (* name *), _ (* typbinds *), _ (* sort *), _ (* pat *), _ (* fields *) ) ->     
+  | ClassD (id, _ (* name *), _ (* typbinds *), _ (* sort *), _ (* pat *), _ (* id *), _ (* fields *) ) ->
     let func_typ = typ dec in
     let v = fresh_id func_typ in 
     let u = fresh_id T.unit in
@@ -906,7 +906,7 @@ and declare_dec dec exp : exp =
   | LetD (pat, _) -> declare_pat pat exp
   | VarD (id, exp1) -> declare_id id (T.Mut (typ exp1)) exp
   | FuncD (_, id, _, _, _, _)
-  | ClassD (id, _, _, _, _, _) -> declare_id id (typ dec) exp
+  | ClassD (id, _, _, _, _, _, _) -> declare_id id (typ dec) exp
 
 and declare_decs decs exp : exp =
   match decs with
diff --git a/src/compile.ml b/src/compile.ml
index d6fe0f1ddaf..84af0fead74 100644
--- a/src/compile.ml
+++ b/src/compile.ml
@@ -3194,7 +3194,7 @@ and compile_dec last pre_env dec : E.t * G.t * (E.t -> G.t) = match dec.it with
       Closure.dec pre_env last name captured mk_pat mk_body dec.at
 
   (* Classes are desguared to functions and objects. *)
-  | ClassD (name, _, typ_params, s, p, efs) ->
+  | ClassD (name, _, typ_params, s, p, self, efs) ->
       let captured = Freevars.captured_exp_fields p efs in
       let mk_pat env1 = compile_mono_pat env1 p in
       let mk_body env1 compile_fun_identifier =
@@ -3206,7 +3206,7 @@ and compile_dec last pre_env dec : E.t * G.t * (E.t -> G.t) = match dec.it with
 	identifier, as provided by Func.dec:
 	For closures it is the pointer to the closure.
 	For functions it is the function id (shifted to never class with pointers) *)
-        Object.lit env1 None (Some compile_fun_identifier) fs' in
+        Object.lit env1 (Some self) (Some compile_fun_identifier) fs' in
       Closure.dec pre_env last name captured mk_pat mk_body dec.at
 
 and compile_decs env decs : G.t = snd (compile_decs_block env true decs)
diff --git a/src/freevars.ml b/src/freevars.ml
index 921323440f4..83911d680ba 100644
--- a/src/freevars.ml
+++ b/src/freevars.ml
@@ -103,8 +103,8 @@ and dec d = match d.it with
   | FuncD (s, i, tp, p, t, e) ->
     (S.empty, S.singleton i.it) +++ (exp e /// pat p)
   | TypD (i, tp, t) -> (S.empty, S.empty)
-  | ClassD (i, l, tp, s, p, efs) ->
-    (S.empty, S.singleton i.it) +++ (close (exp_fields efs) /// pat p)
+  | ClassD (i, l, tp, s, p, i', efs) ->
+    (S.empty, S.singleton i.it) +++ (close (exp_fields efs) /// pat p // i'.it)
 
 (* The variables captured by a function. May include the function itself! *)
 and captured p e = S.elements (exp e /// pat p)
diff --git a/src/interpret.ml b/src/interpret.ml
index 1444ff72119..03ed0a89a61 100644
--- a/src/interpret.ml
+++ b/src/interpret.ml
@@ -251,11 +251,11 @@ and interpret_exp_mut env exp (k : V.value V.cont) =
   | ProjE (exp1, n) ->
     interpret_exp env exp1 (fun v1 -> k (List.nth (V.as_tup v1) n))
   | ObjE (sort, id, fields) ->
-    interpret_obj env sort id fields k
+    interpret_obj env sort id None fields k
   | DotE (exp1, {it = Name n;_}) ->
     interpret_exp env exp1 (fun v1 ->
       let _, fs = V.as_obj v1 in
-      k (try find n fs with _ -> (assert false))
+      k (try find n fs with _ -> assert false)
     )
   | AssignE (exp1, exp2) ->
     interpret_exp_mut env exp1 (fun v1 ->
@@ -539,28 +539,21 @@ and match_pats pats vs ve : val_env option =
 
 (* Objects *)
 
-and interpret_obj env sort id fields (k : V.value V.cont) =
-  let ve0 = declare_id id in
-  let private_ve, public_ve = declare_exp_fields fields ve0 V.Env.empty in
-  let env' = adjoin_vals env private_ve in
-  interpret_fields env' sort.it None fields public_ve (fun v ->
-    define_id (adjoin_vals env ve0) id v;
+and interpret_obj env sort id co fields (k : V.value V.cont) =
+  let ve = declare_exp_fields fields (declare_id id) in
+  let env' = adjoin_vals env ve in
+  interpret_fields env' sort.it co fields V.Env.empty (fun v ->
+    define_id env' id v;
     k v
   )
 
-and declare_field (id,name) =
-  let p = Lib.Promise.make () in
-  V.Env.singleton id.it p,
-  V.Env.singleton (string_of_name name.it) p
-  
-                   
-and declare_exp_fields fields private_ve public_ve : val_env * val_env =
+and declare_exp_fields fields ve : val_env =
   match fields with
-  | [] -> private_ve, public_ve
+  | [] -> ve
   | {it = {id; name; mut; priv; _}; _}::fields' ->
-    let private_ve', public_ve' = declare_field (id,name) in
-    declare_exp_fields fields'
-      (V.Env.adjoin private_ve private_ve') (V.Env.adjoin public_ve public_ve')
+    let p = Lib.Promise.make () in
+    let ve' = V.Env.singleton id.it p in
+    declare_exp_fields fields' (V.Env.adjoin ve ve')
 
 
 and interpret_fields env s co fields ve (k : V.value V.cont) =
@@ -574,7 +567,11 @@ and interpret_fields env s co fields ve (k : V.value V.cont) =
         | Var -> V.Mut (ref v)
       in
       define_id env id v';
-      interpret_fields env s co fields' ve k
+      let ve' =
+        if priv.it = Private
+        then ve
+        else V.Env.add (string_of_name name.it) (V.Env.find id.it env.vals) ve
+      in interpret_fields env s co fields' ve' k
     )
 
 (* Blocks and Declarations *)
@@ -592,7 +589,7 @@ and declare_dec dec : val_env =
   | LetD (pat, _) -> declare_pat pat
   | VarD (id, _)
   | FuncD (_, id, _, _, _, _)
-  | ClassD (id, _, _, _, _, _) -> declare_id id
+  | ClassD (id, _, _, _, _, _, _) -> declare_id id
 
 and declare_decs decs ve : val_env =
   match decs with
@@ -630,16 +627,10 @@ and interpret_dec env dec (k : V.value V.cont) =
     in                      
     define_id env id v;
     k v
-  | ClassD (id, _,  _typbinds, sort, pat, fields) ->
+  | ClassD (id, _,  _typbinds, sort, pat, id', fields) ->
     let c = V.new_class () in
     let f = interpret_func env id pat
-      (fun env' k' ->
-        let private_ve, public_ve =
-          declare_exp_fields fields V.Env.empty V.Env.empty in
-        interpret_fields (adjoin_vals env' private_ve) sort.it (Some c)
-          fields public_ve k'
-      )
-    in
+      (fun env' k' -> interpret_obj env' sort id' (Some c) fields k') in
     let v = V.Func (Some c, f) in
     define_id env id v;
     k v
diff --git a/src/parser.mly b/src/parser.mly
index 3fe9e6882bb..9f5259c89ba 100644
--- a/src/parser.mly
+++ b/src/parser.mly
@@ -535,14 +535,15 @@ dec_nonexp :
     { (fd s (xf "func" $sloc)).it @? at $sloc }
   | TYPE x=id tps=typ_params_opt EQ t=typ
     { TypD(x, tps, t) @? at $sloc }
-  | s=obj_sort_opt CLASS xf=id_opt tps=typ_params_opt p=pat_nullary efs=class_body
-    { let efs' =
+  | s=obj_sort_opt CLASS xf=id_opt tps=typ_params_opt p=pat_nullary xefs=class_body
+    { let x, efs = xefs in
+      let efs' =
         if s.it = Type.Object Type.Local
         then efs
         else List.map share_expfield efs
       in
       let id as tid = xf "class" $sloc in	
-      ClassD(xf "class" $sloc, tid, tps, s, p, efs') @? at $sloc }
+      ClassD(xf "class" $sloc, tid, tps, s, p, x, efs') @? at $sloc }
 dec :
   | d=dec_nonexp
     { d }
@@ -568,8 +569,8 @@ func_body :
   | e=exp_block { (true, e) }
 
 class_body :
-  | EQ efs=exp_obj { efs }
-  | efs=exp_obj { efs }
+  | EQ xf=id_opt efs=exp_obj { xf "object" $sloc, efs }
+  | efs=exp_obj { ("anon-object-" ^ string_of_pos (at $sloc).left) @@ at $sloc, efs }
 
 
 (* Programs *)
diff --git a/src/rename.ml b/src/rename.ml
index 0b28a63c235..dd912ba4686 100644
--- a/src/rename.ml
+++ b/src/rename.ml
@@ -156,13 +156,13 @@ and dec' rho d = match d with
   | TypD (i, tp, t) -> (* we don't rename type names *)
      (fun rho -> d),
      rho
-  | ClassD (i, l, tp, s, p, efs) ->
-     (* TBR - we can't really alpha-convert class constructors - should we internally separate type name from constructor name *)
+  | ClassD (i, l, tp, s, p, i2, efs) ->
     let i',rho = id_bind rho i in
      (fun rho' ->
        let p',rho'' = pat rho' p in
-       let efs' = exp_fields rho'' efs in
-       ClassD(i', l, tp, s, p', efs')),
+       let i2',rho''' = id_bind rho'' i2 in
+       let efs' = exp_fields rho''' efs in
+       ClassD(i', l, tp, s, p', i2', efs')),
       rho
        
 and decs rho ds =
diff --git a/src/syntax.ml b/src/syntax.ml
index 0e724838578..cb1b6132825 100644
--- a/src/syntax.ml
+++ b/src/syntax.ml
@@ -14,6 +14,7 @@ type name = name' Source.phrase
 and name' = Name of string                
 let string_of_name (Name s ) = s              
 
+
 (* Types *)
 
 type sharing = Type.sharing Source.phrase
@@ -159,7 +160,7 @@ and exp' =
   | DecE of dec                                (* declaration *)
   | DeclareE of id * Type.typ * exp            (* local promise (internal) *)
   | DefineE of id * mut * exp                  (* promise fulfillment (internal) *)
-  | NewObjE of obj_sort * (name*id) list       (* make an object, preserving mutable identity (internal) *)                          
+  | NewObjE of obj_sort * (name * id) list     (* make an object, preserving mutable identity (internal) *)
 (*
   | ThrowE of exp list                         (* throw exception *)
   | TryE of exp * case list                    (* catch eexception *)
@@ -168,7 +169,7 @@ and exp' =
 *)
 
 and exp_field = exp_field' Source.phrase
-and exp_field' = {name: name; id : id; exp : exp; mut : mut; priv : priv}
+and exp_field' = {name : name; id : id; exp : exp; mut : mut; priv : priv}
 
 and case = case' Source.phrase
 and case' = {pat : pat; exp : exp}
@@ -183,7 +184,7 @@ and dec' =
   | VarD of id * exp                                   (* mutable *)
   | FuncD of sharing * id * typ_bind list * pat * typ * exp (* function *)
   | TypD of id * typ_bind list * typ                   (* type *)
-  | ClassD of id (* term id*) * id (*type id*) * typ_bind list * obj_sort * pat * exp_field list (* class *)
+  | ClassD of id (*term id*) * id (*type id*) * typ_bind list * obj_sort * pat * id * exp_field list (* class *)
 
 
 (* Program *)
diff --git a/src/type.ml b/src/type.ml
index edf1447aa0a..1b68053880b 100644
--- a/src/type.ml
+++ b/src/type.ml
@@ -362,7 +362,7 @@ let rec avoid' env env' = function
           List.map (avoid' env env') ts1, List.map (avoid' env env') ts2)
   | Opt t -> Opt (avoid' env env' t)
   | Async t -> Async (avoid' env env' t)
-  | Like t -> Like (avoid' env env' t)
+  | Like t -> avoid' env env' (promote env t)
   | Obj (s, fs) -> Obj (s, List.map (avoid_field env env') fs)
   | Mut t -> Mut (avoid' env env' t)
 
@@ -386,7 +386,7 @@ let rel_list p env rel eq xs1 xs2 =
 
 let str = ref (fun _ -> failwith "")
 let rec rel_typ env rel eq t1 t2 =
-(*printf "[sub] %s == %s\n" (string_of_typ t1) (string_of_typ t2); flush_all();*)
+(*Printf.printf "[sub] %s == %s\n%!" (!str t1) (!str t2);*)
   t1 == t2 || S.mem (t1, t2) !rel || begin
   rel := S.add (t1, t2) !rel;
   match t1, t2 with
@@ -477,10 +477,10 @@ let rec rel_typ env rel eq t1 t2 =
     rel_typ env rel eq t1' t2'
   | Async t1', Shared ->
     rel_typ env rel eq t1' Shared
-  | Like t1', Like t2' ->
-    rel_typ env rel eq t1' t2'
-  | Like t1', Shared ->
-    rel_typ env rel eq t1' Shared
+  | Like t1', t2 ->
+    rel_typ env rel eq (promote env t1') t2
+  | t1, Like t2' ->
+    rel_typ env rel eq t1 (promote env t2')
   | Mut t1', Mut t2' ->
     eq_typ env rel eq t1' t2'
   | _, _ -> false
diff --git a/src/typing.ml b/src/typing.ml
index 1f3a7b86d96..52034a2e45b 100644
--- a/src/typing.ml
+++ b/src/typing.ml
@@ -63,12 +63,14 @@ let empty_env =
 
 let add_lab c x t = {c with labs = T.Env.add x t c.labs}
 let add_val c x t = {c with vals = T.Env.add x t c.vals}
-(*let add_con c con k = {c with cons = Con.Env.add con k c.cons}*)
+(*
+let add_con c con k = {c with cons = Con.Env.add con k c.cons}
 let add_typ c x con k =
   { c with
     typs = T.Env.add x con c.typs;
     cons = Con.Env.add con k c.cons;
   }
+*)
 
 let add_typs c xs cs ks =
   { c with
@@ -374,7 +376,7 @@ and infer_exp' env exp : T.typ =
         (T.string_of_typ_expand env.cons t1)
     )
   | ObjE (sort, id, fields) ->
-    fst (infer_obj env sort.it id fields)
+    infer_obj env sort.it id fields
   | DotE (exp1, {it = Name n;_}) ->
     let t1 = infer_exp_promote env exp1 in
     (try
@@ -822,33 +824,19 @@ and check_pats env ts pats ve at : val_env =
 
 (* Objects *)
 
-and infer_obj env s id fields : T.typ * T.typ =
-  (* TBR: rethink private *)
-(*Printf.printf "[object] gather fields, env:\n";
-print_ce env.cons;
-print_ve env.vals;*)
+and infer_obj env s id fields : T.typ =
   let pre_ve = gather_exp_fields id.it fields in
-(*Printf.printf "[object] pre-infer fields\n";*)
   let pre_env = adjoin_vals {env with pre = true} pre_ve in
-  let tfs, tfs_inner, ve = infer_exp_fields pre_env s id.it T.Pre fields in
-  let t_inner = T.Obj (s, tfs_inner) in
-(*print_ve ve;
-Printf.printf "[object] infer fields, env:\n";
-print_ce env.cons;
-print_ve (adjoin_vals (add_val env id.it ((*t*) t_inner, T.Const)) ve).vals;*)
+  let tfs, ve = infer_exp_fields pre_env s id.it T.Pre fields in
+  let t = T.Obj (s, tfs) in
   if not env.pre then begin
-    let env' = adjoin_vals (add_val env id.it (*t*) t_inner) ve in
-    ignore (infer_exp_fields env' s id.it (*t*) t_inner fields)
+    let env' = adjoin_vals (add_val env id.it t) ve in
+    ignore (infer_exp_fields env' s id.it t fields)
   end;
-(*Printf.printf "[object] done\n";*)
-  T.Obj (s, tfs), t_inner
+  t
 
 
 and check_obj env s tfs id fields at : T.typ =
-  (* TBR: rethink private *)
-(*Printf.printf "[object] gather fields, env:\n";
-print_ce env.cons;
-print_ve env.vals;*)
   let pre_ve = gather_exp_fields id.it fields in
   let pre_ve' = List.fold_left (fun ve {T.name; typ = t} ->
       if not (T.Env.mem name ve) then
@@ -858,18 +846,12 @@ print_ve env.vals;*)
       T.Env.add name t ve
     ) pre_ve tfs
   in
-(*Printf.printf "[object] pre-infer fields\n";*)
   let pre_env = adjoin_vals {env with pre = true} pre_ve' in
-  let _, tfs_inner, ve = infer_exp_fields pre_env s id.it T.Pre fields in
-  let t_inner = T.Obj (s, tfs_inner) in
-(*print_ve ve;
-Printf.printf "[object] infer fields, env:\n";
-print_ce env.cons;
-print_ve (adjoin_vals (add_val env id.it ((*t*) t_inner, T.Const)) ve).vals;*)
-  let env' = adjoin_vals (add_val env id.it (*t*) t_inner) ve in
-  ignore (infer_exp_fields env' s id.it (*t*) t_inner fields);
-(*Printf.printf "[object] done\n";*)
-  t_inner
+  let tfs, ve = infer_exp_fields pre_env s id.it T.Pre fields in
+  let t = T.Obj (s, tfs) in
+  let env' = adjoin_vals (add_val env id.it t) ve in
+  ignore (infer_exp_fields env' s id.it t fields);
+  t
 
 
 and gather_exp_fields id fields : val_env =
@@ -883,11 +865,11 @@ and gather_exp_field ve field : val_env =
   T.Env.add id.it T.Pre ve
 
 
-and infer_exp_fields env s id t fields : T.field list * T.field list * val_env =
+and infer_exp_fields env s id t fields : T.field list * val_env =
   let env' = add_val env id t in
-  let tfs, tfs_inner, ve =
-    List.fold_left (infer_exp_field env' s) ([], [], T.Env.empty) fields in
-  List.sort compare tfs, List.sort compare tfs_inner, ve
+  let tfs, ve =
+    List.fold_left (infer_exp_field env' s) ([], T.Env.empty) fields in
+  List.sort compare tfs, ve
 
 and is_func_exp exp =
   match exp.it with
@@ -900,7 +882,7 @@ and is_func_dec dec =
   | FuncD _ -> true
   | _ -> Printf.printf "[2]%!"; false
 
-and infer_exp_field env s (tfs, tfs_inner, ve) field : T.field list * T.field list * val_env =
+and infer_exp_field env s (tfs, ve) field : T.field list * val_env =
   let {id; name; exp; mut; priv} = field.it in
   let t =
     match T.Env.find id.it env.vals with
@@ -920,55 +902,31 @@ and infer_exp_field env s (tfs, tfs_inner, ve) field : T.field list * T.field li
         (string_of_name name.it) (T.string_of_typ_expand env.cons t)
   end;
   let ve' = T.Env.add id.it t ve in
-  let tfs_inner' = {T.name = string_of_name name.it; typ = t} :: tfs_inner in
   let tfs' =
-    if priv.it = Private then tfs else {T.name = string_of_name name.it; typ = t} :: tfs
-  in tfs', tfs_inner', ve'
-
-
-(*
-and check_exp_fields env s tfs id t fields : T.field list * val_env =
-  let env' = add_val env id t in
-  let tfs_inner, ve =
-    List.fold_left (check_exp_field env' s tfs) ([], T.Env.empty) fields in
-  List.sort compare tfs_inner, ve
-
-and check_exp_field env s tfs (tfs_inner, ve) field : T.field list * val_env =
-  let {id; exp; mut; priv} = field.it in
-  if priv = Private then begin
-    let _, tfs_inner', ve' =
-      infer_exp_field env s ([], tfs_inner, ve) field
-    in tfs_inner', ve'
-  end else begin
-    check_exp (adjoin_vals env ve) (T.Env.find env.vals id.it) exp;
-    if s = T.Actor && priv.it = Public && not (is_async_typ env t) then
-      error field.at "public actor field %s has non-async type %s"
-        id.it (T.string_of_typ t)
-  end;
-  let ve' = T.Env.add id.it t ve in
-  let tfs_inner' = {T.name = id.it; typ = t} :: tfs_inner in
-  tfs_inner', ve'
-*)
+    if priv.it = Private
+    then tfs
+    else {T.name = string_of_name name.it; typ = t} :: tfs
+  in tfs', ve'
 
 
 (* Blocks and Declarations *)
 
 and infer_block env decs at : T.typ * scope =
-  let _, _, ce as scope, ce_inner = infer_block_decs env decs in
-  let t = infer_block_exps (adjoin env scope) ce_inner decs in
+  let _, _, ce as scope = infer_block_decs env decs in
+  let t = infer_block_exps (adjoin env scope) decs in
   t, scope
 
-and infer_block_exps env ce_inner decs : T.typ =
+and infer_block_exps env decs : T.typ =
   match decs with
   | [] -> T.unit
-  | [dec] -> infer_dec env ce_inner dec
+  | [dec] -> infer_dec env dec
   | dec::decs' ->
     let errs1 =
-      if env.pre then [] else recover (check_dec env ce_inner T.unit) dec in
-    let t, errs2 = recover_with T.Non (infer_block_exps env ce_inner) decs' in
+      if env.pre then [] else recover (check_dec env T.unit) dec in
+    let t, errs2 = recover_with T.Non (infer_block_exps env) decs' in
     return_with t (errs1 @ errs2)
 
-and infer_dec env ce_inner dec : T.typ =
+and infer_dec env dec : T.typ =
   let t = 
   match dec.it with
   | ExpD exp ->
@@ -988,17 +946,15 @@ and infer_dec env ce_inner dec : T.typ =
       check_exp (adjoin_vals env'' ve) t2 exp
     end;
     t
-  | ClassD (id, tid, typbinds, sort, pat, fields) ->
+  | ClassD (id, tid, typbinds, sort, pat, id', fields) ->
     let t = T.Env.find id.it env.vals in
     if not env.pre then begin
       let _cs, _ts, te, ce = check_typ_binds env typbinds in
       let env' = adjoin_typs env te ce in
-      let c = T.Env.find tid.it env.typs in
-      let env' = (*env'*) add_typ env' tid.it c (Con.Env.find c ce_inner) in
       let _, ve = infer_pat_exhaustive env' pat in
       let env'' =
         {env' with labs = T.Env.empty; rets = None; async = false} in
-      ignore (infer_obj (adjoin_vals env'' ve) sort.it ("anon-self" @@ no_region) fields)
+      ignore (infer_obj (adjoin_vals env'' ve) sort.it id' fields)
     end;
     t
   | TypD _ ->
@@ -1011,37 +967,34 @@ and infer_dec env ce_inner dec : T.typ =
 
 
 and check_block env t decs at : scope =
-  let scope, ce_inner = infer_block_decs env decs in
-(*Printf.printf "[block] check expressions\n";*)
-  check_block_exps (adjoin env scope) ce_inner t decs at;
-(*Printf.printf "[block] done\n";*)
+  let scope = infer_block_decs env decs in
+  check_block_exps (adjoin env scope) t decs at;
   scope
 
-and check_block_exps env ce_inner t decs at =
+and check_block_exps env t decs at =
   match decs with
   | [] ->
     if not (T.sub env.cons T.unit t) then
       error at "empty block cannot produce expected type\n  %s"
         (T.string_of_typ_expand env.cons t)
   | [dec] ->
-    check_dec env ce_inner t dec
+    check_dec env t dec
   | dec::decs' ->
-    let errs1 = recover (check_dec env ce_inner T.unit) dec in
-    let errs2 = recover (check_block_exps env ce_inner t decs') at in
+    let errs1 = recover (check_dec env T.unit) dec in
+    let errs2 = recover (check_block_exps env t decs') at in
     return (errs1 @ errs2)
 
-and check_dec env ce_inner t dec =
-  begin
-    match dec.it with
-    | ExpD exp ->
-       check_exp env t exp;
-       dec.note <- exp.note;
+and check_dec env t dec =
+  match dec.it with
+  | ExpD exp ->
+    check_exp env t exp;
+    dec.note <- exp.note;
 (* TBR: push in external type annotation;
    unfortunately, this is enough, because of the earlier recursive phases
   | FuncD (id, [], pat, typ, exp) ->
     (* TBR: special-case unit? *)
     if T.eq env.cons t T.unit then
-      ignore (infer_dec env ce_inner dec)
+      ignore (infer_dec env dec)
     else
     (match T.nonopt env.cons t with
     | T.Func ([], t1, t2)->
@@ -1059,14 +1012,13 @@ and check_dec env ce_inner t dec =
         (T.string_of_typ t)
     )
  *)
-    | _ ->
-       let t' = infer_dec env ce_inner dec in
-       (* TBR: special-case unit? *)
-       if not (T.eq env.cons t T.unit || T.sub env.cons t' t) then
-         error dec.at "expression of type\n  %s\ncannot produce expected type\n  %s"
-           (T.string_of_typ_expand env.cons t)
-           (T.string_of_typ_expand env.cons t');
-  end;
+  | _ ->
+     let t' = infer_dec env dec in
+     (* TBR: special-case unit? *)
+     if not (T.eq env.cons t T.unit || T.sub env.cons t' t) then
+       error dec.at "expression of type\n  %s\ncannot produce expected type\n  %s"
+         (T.string_of_typ_expand env.cons t)
+         (T.string_of_typ_expand env.cons t')
   
 (*
 and print_ce =
@@ -1080,24 +1032,17 @@ and print_ve =
 *)
 
 
-and infer_block_decs env decs : scope * con_env =
-(*Printf.printf "[block] gather types\n";*)
+and infer_block_decs env decs : scope =
   let pre_ve, te, pre_ce = gather_block_typdecs decs in
-(*Printf.printf "[block] pre-infer types\n";*)
   let env' = adjoin {env with pre = true} (pre_ve, te, pre_ce) in
-  let ce, _ = infer_block_typdecs env' decs in
-(*Printf.printf "[block] infer types\n";*)
+  let ce = infer_block_typdecs env' decs in
   let env'' = adjoin env (pre_ve, te, ce) in
-  let ce', ce_inner = infer_block_typdecs env'' decs in
+  let _ce' = infer_block_typdecs env'' decs in
   (* TBR: assertion does not work for types with binders, due to stamping *)
   (* assert (ce = ce'); *)
-(*print_ce ce;*)
-(*Printf.printf "[block] gather values\n";*)
   let pre_ve' = gather_block_valdecs decs in
-(*Printf.printf "[block] infer values\n";*)
   let ve = infer_block_valdecs (adjoin_vals env'' pre_ve') decs in
-(*print_ve ve;*)
-  (ve, te, ce), ce_inner
+  (ve, te, ce)
 
 
 (* Pass 1: collect type identifiers and their arity *)
@@ -1108,7 +1053,7 @@ and gather_block_typdecs decs : scope =
 and gather_dec_typdecs (ve, te, ce) dec : scope =
   match dec.it with
   | ExpD _ | LetD _ | VarD _ | FuncD _ -> ve, te, ce
-  | TypD (id, binds, _) | ClassD (_, id, binds, _, _, _) ->
+  | TypD (id, binds, _) | ClassD (_, id, binds, _, _, _, _) ->
     if T.Env.mem id.it te then
       error dec.at "duplicate definition for type %s in block" id.it;
     let cs =
@@ -1118,7 +1063,7 @@ and gather_dec_typdecs (ve, te, ce) dec : scope =
     let pre_k = T.Abs (pre_tbs, T.Pre) in
     let ve' =
       match dec.it with
-      | ClassD (conid, _, _ , _, _, _) ->
+      | ClassD (conid, _, _ , _, _, _, _) ->
         let t2 = T.Con (c, List.map (fun c' -> T.Con (c', [])) cs) in
         T.Env.add conid.it (T.Func (T.Construct, T.Returns, pre_tbs, [T.Pre], [t2])) ve
       | _ -> ve
@@ -1126,35 +1071,33 @@ and gather_dec_typdecs (ve, te, ce) dec : scope =
 
 
 (* Pass 2 and 3: infer type definitions *)
-and infer_block_typdecs env decs : con_env * con_env =
-  let _env', ce, ce_inner =
-    List.fold_left (fun (env, ce, ce_inner) dec ->
-      let ce', ce_inner' = infer_dec_typdecs env dec in
-      adjoin_cons env ce', Con.Env.adjoin ce ce',
-        Con.Env.adjoin ce_inner ce_inner'
-    ) (env, Con.Env.empty, Con.Env.empty) decs
-  in ce, ce_inner
-
-and infer_dec_typdecs env dec : con_env * con_env =
+and infer_block_typdecs env decs : con_env =
+  let _env', ce =
+    List.fold_left (fun (env, ce) dec ->
+      let ce' = infer_dec_typdecs env dec in
+      adjoin_cons env ce', Con.Env.adjoin ce ce'
+    ) (env, Con.Env.empty) decs
+  in ce
+
+and infer_dec_typdecs env dec : con_env =
   match dec.it with
   | ExpD _ | LetD _ | VarD _ | FuncD _ ->
-    Con.Env.empty, Con.Env.empty
+    Con.Env.empty
   | TypD (id, binds, typ) ->
     let c = T.Env.find id.it env.typs in
     let cs, ts, te, ce = check_typ_binds {env with pre = true} binds in
     let env' = adjoin_typs env te ce in
     let t = check_typ env' typ in
     let tbs = List.map2 (fun c t -> {T.var = Con.name c; bound = T.close cs t}) cs ts in
-    Con.Env.singleton c (T.Def (tbs, T.close cs t)), Con.Env.empty
-  | ClassD (conid, id, binds, sort, pat, fields) ->
+    Con.Env.singleton c (T.Def (tbs, T.close cs t))
+  | ClassD (conid, id, binds, sort, pat, id', fields) ->
     let c = T.Env.find id.it env.typs in
     let cs, ts, te, ce = check_typ_binds {env with pre = true} binds in
     let env' = adjoin_typs {env with pre = true} te ce in
     let _, ve = infer_pat env' pat in
-    let t, t_inner = infer_obj (adjoin_vals env' ve) sort.it ("anon-self" @@ no_region) fields in
+    let t = infer_obj (adjoin_vals env' ve) sort.it id' fields in
     let tbs = List.map2 (fun c t -> {T.var = Con.name c; bound = T.close cs t}) cs ts in
-    Con.Env.singleton c (T.Abs (tbs, T.close cs t)),
-    Con.Env.singleton c (T.Abs (tbs, T.close cs t_inner))
+    Con.Env.singleton c (T.Abs (tbs, T.close cs t))
 
 
 (* Pass 4: collect value identifiers *)
@@ -1167,7 +1110,7 @@ and gather_dec_valdecs ve dec : val_env =
     ve
   | LetD (pat, _) ->
     gather_pat ve pat
-  | VarD (id, _) | FuncD (_, id, _, _, _, _) | ClassD (id, _ , _, _, _, _) ->
+  | VarD (id, _) | FuncD (_, id, _, _, _, _) | ClassD (id, _ , _, _, _, _, _) ->
     if T.Env.mem id.it ve then
       error dec.at "duplicate definition for %s in block" id.it;
     T.Env.add id.it T.Pre ve
@@ -1229,7 +1172,7 @@ and infer_dec_valdecs env dec : val_env =
       (T.Func (T.Call sort.it, c, tbs, List.map (T.close cs) ts1, List.map (T.close cs) ts2))
   | TypD _ ->
     T.Env.empty
-  | ClassD (conid, id, typbinds, sort, pat, fields) ->
+  | ClassD (conid, id, typbinds, sort, pat, id', fields) ->
     let cs, ts, te, ce = check_typ_binds env typbinds in
     let env' = adjoin_typs env te ce in
     let c = T.Env.find id.it env.typs in
diff --git a/test/run/account.as b/test/run/account.as
index 5d4c2fed1d5..c52992967bd 100644
--- a/test/run/account.as
+++ b/test/run/account.as
@@ -1,4 +1,4 @@
-actor class Account(initialBalance : Int) {
+actor class Account(initialBalance : Int) = this {
   private var balance : Int = initialBalance;
 
   getBalance() : async Int {
@@ -10,15 +10,15 @@ actor class Account(initialBalance : Int) {
     return Account(amount);
   };
 
-  join(account : Account) {  // this implicitly asserts that account is Account
+  join(account : like Account) {
+    assert(account is Account);
     let amount = balance;
-    balance := +0;
-    account.credit(amount);
+    balance := 0;
+    account.credit(amount, Account);
   };
 
-  private credit(amount : Int) {
-    // private implicitly asserts that caller is own class
-    // by implicitly passing the modref as an extra argument
+  credit(amount : Int, caller : Class) {
+    assert(this is caller);
     balance += amount;
   };
 
diff --git a/test/run/actor.as b/test/run/actor.as
index 8c680a9f20b..ca7a23d3b97 100644
--- a/test/run/actor.as
+++ b/test/run/actor.as
@@ -68,7 +68,7 @@ let f = async {
 		  private get_a = await (async (func get_a() : async Text {a;}));
 		  private get_b = await (async (func get_b() : async Text {b;}));
 		  get_ab(): async (Text,Text) {
-   		    (await get_a(), await this.get_b());
+   		    (await get_a(), await get_b());
 		  };
 		  };
    let (a,b) = await(o.get_ab());
diff --git a/test/run/bank-example.as b/test/run/bank-example.as
index 7dec3e5784e..12f1f7b50eb 100644
--- a/test/run/bank-example.as
+++ b/test/run/bank-example.as
@@ -12,7 +12,7 @@ actor class Issuer() {
   };
 };
 
-actor class Account(initialBalance : Int) {
+actor class Account(initialBalance : Int) = self {
   private var balance : Int = initialBalance;
 
   getBalance() : async Int {
@@ -24,15 +24,15 @@ actor class Account(initialBalance : Int) {
     return Account(amount);
   };
 
-  join(account : Account) {  // this implicitly asserts that account is Account
+  join(account : like Account) {
+    assert(account is Account);
     let amount = balance;
     balance := 0;
-    account.credit(amount);
+    account.credit(amount, Account);
   };
 
-  private credit(amount : Int) {
-    // private implicitly asserts that caller is own class
-    // by implicitly passing the modref as an extra argument
+  credit(amount : Int, caller : Class) {
+    assert(self is caller);
     balance += amount;
   };
 
diff --git a/test/run/bank-ordered.as b/test/run/bank-ordered.as
index 9b722ba973d..3e62b2732e5 100644
--- a/test/run/bank-ordered.as
+++ b/test/run/bank-ordered.as
@@ -1,6 +1,6 @@
 // Like bank.as but in dependency order
 
-actor class Account(initialBalance : Int) {
+actor class Account(initialBalance : Int) = this {
   private var balance : Int = initialBalance;
 
   getBalance() : async Int {
@@ -12,15 +12,15 @@ actor class Account(initialBalance : Int) {
     return Account(amount);
   };
 
-  join(account : Account) {  // this implicitly asserts that account is Account
+  join(account : like Account) {
+    assert(account is Account);
     let amount = balance;
     balance := +0;  // Hack!
-    account.credit(amount);
+    account.credit(amount, Account);
   };
 
-  private credit(amount : Int) {
-    // private implicitly asserts that caller is own class
-    // by implicitly passing the modref as an extra argument
+  credit(amount : Int, caller : Class) {
+    assert(this is caller);
     balance += amount;
   };
 
diff --git a/test/run/bank.as b/test/run/bank.as
index 77cc3fd8ca9..0747c8e6229 100644
--- a/test/run/bank.as
+++ b/test/run/bank.as
@@ -11,7 +11,7 @@ actor class Issuer() {
   };
 };
 
-actor class Account(initialBalance : Int) {
+actor class Account(initialBalance : Int) = self {
   private var balance : Int = initialBalance;
 
   getBalance() : async Int {
@@ -23,15 +23,15 @@ actor class Account(initialBalance : Int) {
     return Account(amount);
   };
 
-  join(account : Account) {  // this implicitly asserts that account is Account
+  join(account : like Account) {
+    assert(account is Account);
     let amount = balance;
     balance := 0;
-    account.credit(amount);
+    account.credit(amount, Account);
   };
 
-  private credit(amount : Int) {
-    // private implicitly asserts that caller is own class
-    // by implicitly passing the modref as an extra argument
+  credit(amount : Int, caller : Class) {
+    assert(self is caller);
     balance += amount;
   };
 
diff --git a/test/run/ok/account.wasm-run.ok b/test/run/ok/account.wasm-run.ok
new file mode 100644
index 00000000000..d7648f54f23
--- /dev/null
+++ b/test/run/ok/account.wasm-run.ok
@@ -0,0 +1 @@
+_out/account.wasm:0x___: runtime trap: unreachable executed
diff --git a/test/run/ok/account.wasm.stderr.ok b/test/run/ok/account.wasm.stderr.ok
index 4ef479755e2..36cd23d940c 100644
--- a/test/run/ok/account.wasm.stderr.ok
+++ b/test/run/ok/account.wasm.stderr.ok
@@ -1 +1,2 @@
+Could not find this
 Could not find Account
diff --git a/test/run/ok/bank-example.wasm-run.ok b/test/run/ok/bank-example.wasm-run.ok
new file mode 100644
index 00000000000..b84483e8c59
--- /dev/null
+++ b/test/run/ok/bank-example.wasm-run.ok
@@ -0,0 +1 @@
+_out/bank-example.wasm:0x___: runtime trap: unreachable executed
diff --git a/test/run/ok/bank-example.wasm.stderr.ok b/test/run/ok/bank-example.wasm.stderr.ok
index 41346f1f179..a3a7bdead84 100644
--- a/test/run/ok/bank-example.wasm.stderr.ok
+++ b/test/run/ok/bank-example.wasm.stderr.ok
@@ -1,2 +1,3 @@
+Could not find self
 Could not find Account
 Could not find Account
diff --git a/test/run/ok/bank-ordered.wasm-run.ok b/test/run/ok/bank-ordered.wasm-run.ok
new file mode 100644
index 00000000000..d62cbfac5ec
--- /dev/null
+++ b/test/run/ok/bank-ordered.wasm-run.ok
@@ -0,0 +1 @@
+_out/bank-ordered.wasm:0x___: runtime trap: unreachable executed
diff --git a/test/run/ok/bank-ordered.wasm.stderr.ok b/test/run/ok/bank-ordered.wasm.stderr.ok
index 41346f1f179..7e0dbb3aef3 100644
--- a/test/run/ok/bank-ordered.wasm.stderr.ok
+++ b/test/run/ok/bank-ordered.wasm.stderr.ok
@@ -1,2 +1,3 @@
 Could not find Account
+Could not find this
 Could not find Account
diff --git a/test/run/ok/bank.wasm-run.ok b/test/run/ok/bank.wasm-run.ok
new file mode 100644
index 00000000000..e491abe4726
--- /dev/null
+++ b/test/run/ok/bank.wasm-run.ok
@@ -0,0 +1 @@
+_out/bank.wasm:0x___: runtime trap: unreachable executed
diff --git a/test/run/ok/bank.wasm.stderr.ok b/test/run/ok/bank.wasm.stderr.ok
index 41346f1f179..a3a7bdead84 100644
--- a/test/run/ok/bank.wasm.stderr.ok
+++ b/test/run/ok/bank.wasm.stderr.ok
@@ -1,2 +1,3 @@
+Could not find self
 Could not find Account
 Could not find Account
diff --git a/test/run/ok/this-dot-private.run-low.ok b/test/run/ok/this-dot-private.run-low.ok
deleted file mode 100644
index 265c3b2ee24..00000000000
--- a/test/run/ok/this-dot-private.run-low.ok
+++ /dev/null
@@ -1 +0,0 @@
-fefb
diff --git a/test/run/ok/this-dot-private.run.ok b/test/run/ok/this-dot-private.run.ok
deleted file mode 100644
index 265c3b2ee24..00000000000
--- a/test/run/ok/this-dot-private.run.ok
+++ /dev/null
@@ -1 +0,0 @@
-fefb
diff --git a/test/run/ok/this-dot-private.wasm-run.ok b/test/run/ok/this-dot-private.wasm-run.ok
deleted file mode 100644
index a5166345e75..00000000000
--- a/test/run/ok/this-dot-private.wasm-run.ok
+++ /dev/null
@@ -1 +0,0 @@
-_out/this-dot-private.wasm:0x___: runtime trap: unreachable executed
diff --git a/test/run/ok/this-dot-private.wasm.stderr.ok b/test/run/ok/this-dot-private.wasm.stderr.ok
deleted file mode 100644
index 1958157334c..00000000000
--- a/test/run/ok/this-dot-private.wasm.stderr.ok
+++ /dev/null
@@ -1 +0,0 @@
-compile_exp: (NewObjE Actor get_ab get_ab@7 get_b get_b@6 get_a get_a@5 b b@4 a a@3)
diff --git a/test/run/this-dot-private.as b/test/run/this-dot-private.as
deleted file mode 100644
index 048a2248b3c..00000000000
--- a/test/run/this-dot-private.as
+++ /dev/null
@@ -1,17 +0,0 @@
-/* adapted from ../run/actor.as */
-let f = async {
-   let o = actor this {
-                  private a = "fe";
-                  private b = "fb";
-		  private get_a = await (async (func get_a() : async Text {a;}));
-		  private get_b = await (async (func get_b() : async Text {b;}));
-		  get_ab(): async (Text,Text) {
-		    let _ = (await this.get_a(), await this.get_b());  
-   		    (await get_a(), await get_b())
-		  };
-		  };
-   let (a,b) = await(o.get_ab());
-   print a;
-   print b;
-   print "\n";
-};