--- a/cbc/stack-subtype.agda	Wed Jan 11 13:37:23 2017 +0000
+++ b/cbc/stack-subtype.agda	Wed Jan 11 20:11:01 2017 +0000
@@ -97,49 +97,11 @@
 popSingleLinkedStackCS = M.cs popSingleLinkedStack
 
 
-
-
-
--- sample
-
-record Num : Set where
-  field
-    num : ℕ
+-- for sample
 
-instance
-  NumIsNormalDataSegment : N.DataSegment Num
-  NumIsNormalDataSegment = record { get = (\c -> record { num = Context.n c})
-                                  ; set = (\c n -> record c {n = Num.num n})}
-
-
-plus3 : Num -> Num
-plus3 record { num = n } = record {num = n + 3}
-
-plus3CS : N.CodeSegment Num Num
-plus3CS = N.cs plus3
+firstContext : Context
+firstContext = record { element = nothing ; n = 0}
 
 
-setNext : {X Y : Set} {{x : N.DataSegment X}} {{y : N.DataSegment Y}}
-        -> (N.CodeSegment X Y) -> M.CodeSegment (MetaContext Context) (MetaContext Context)
-setNext c = M.cs (\mc -> record mc {nextCS = liftContext c})
-
-setElement : A -> M.CodeSegment (MetaContext Context) (MetaContext Context)
-setElement x = M.cs (\mc -> record mc {context = record (MetaContext.context mc) {element = just x}})
-
-pushPlus3CS : {mc : MetaContext Context} -> M.CodeSegment (MetaContext Context) (MetaContext Context)
-pushPlus3CS {mc} = M.csComp {mc} pushSingleLinkedStackCS (setNext plus3CS)
-
-plus5AndPush : {mc : MetaContext Context} {{_ : N.DataSegment Num}} {{_ : M.DataSegment Num}}
-               -> M.CodeSegment Num (MetaContext Context)
-plus5AndPush {mc} {{nn}} = M.cs (\n -> record {context = con ; nextCS = (liftContext {{nn}} {{nn}} plus3CS) ; stack = st} )
-  where
-    con  = MetaContext.context mc
-    st   = MetaContext.stack mc
-
-
-push-sample : {{_ : M.DataSegment Num}} -> MetaContext Context
-push-sample = M.exec (plus5AndPush {mc}) mc
-  where
-    con  = record { n = 4 ; element = nothing}
-    code = N.cs (\c -> c)
-    mc   = record {context = con ; stack = emptySingleLinkedStack ; nextCS = code}
+firstMetaContext : MetaContext Context
+firstMetaContext = record {stack = emptySingleLinkedStack ; nextCS = (N.cs (\m -> m)) ; context = firstContext}