--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/paper/src/AgdaPushPop.agda	Mon Jan 27 20:41:36 2020 +0900
@@ -0,0 +1,28 @@
+pushSingleLinkedStack : Meta -> Meta
+pushSingleLinkedStack m = M.exec (liftMeta n) (record m {stack = (push s e) })
+  where
+    n = Meta.nextCS m
+    s = Meta.stack  m
+    e = Context.element (Meta.context m)
+    push : SingleLinkedStack A -> Maybe A -> SingleLinkedStack A
+    push s nothing  = s
+    push s (just x) = record {top = just (cons x (top s))}
+
+popSingleLinkedStack : Meta -> Meta
+popSingleLinkedStack m = M.exec (liftMeta n) (record m {stack = (st m) ; context = record con {element = (elem m)}})
+  where
+    n = Meta.nextCS m
+    con  = Meta.context m
+    elem : Meta -> Maybe A
+    elem record {stack = record { top = (just (cons x _)) }} = just x
+    elem record {stack = record { top = nothing           }} = nothing
+    st : Meta -> SingleLinkedStack A
+    st record {stack = record { top = (just (cons _ s)) }} = record {top = s}
+    st record {stack = record { top = nothing           }} = record {top = nothing}
+
+
+pushSingleLinkedStackCS : M.CodeSegment Meta Meta
+pushSingleLinkedStackCS = M.cs pushSingleLinkedStack
+
+popSingleLinkedStackCS : M.CodeSegment Meta Meta
+popSingleLinkedStackCS = M.cs popSingleLinkedStack