Fix tla-example-with-functor.dl to use list fold functor.

tla-example-with-functor.dl

@@ -97,24 +97,14 @@ ClientServerIndex(c, s, ci*ns + si) :-
   serverId : ServerId
 ]
 
-// .type LockedState = [
-//   serverIndex: number,
-//   rest: LockedState
-// ]
-
-// .type HeldState = [
-//   clientServerIndex: number,
-//   rest: HeldState
-// ]
-
 .type HeldOrLockedState = [
   index: number,
   rest: HeldOrLockedState
 ]
 
 .type State = [
-  locked: LockedState,
-  held: HeldState
+  locked: HeldOrLockedState,
+  held: HeldOrLockedState
 ]
 
 
@@ -168,12 +158,12 @@ DecomposeAction(a, k, c, s) :-
   .decl HeldStateFinalized(prevState: State, action: Action, hstate: HeldOrLockedState)
   HeldStateFinalized(prevState, action, id_list) :-
     PossibleAction(prevState, action),
-    id = @@list_fold i: 0, {Held_Prime_Index(prevState, action, i)}.
+    id_list = @@list_fold i: nil, {Held_Prime_Index(prevState, action, i)}.
 
   .decl LockedStateFinalized(prevState: State, action: Action, lstate: HeldOrLockedState)
   LockedStateFinalized(prevState, action, id_list) :-
     PossibleAction(prevState, action),
-    id = @@list_fold i: 0, {Locked_Prime_Index(prevState, action, i)}.
+    id_list = @@list_fold i: nil, {Locked_Prime_Index(prevState, action, i)}.
 
   .decl TotalStateFinalized(state: State, prevState: State, action: Action)
   TotalStateFinalized([ls, hs], prevState, action) :-