diff --git a/src/Core/Examples.hs b/src/Core/Examples.hs
index 209c15e..a7a7c0a 100644
--- a/src/Core/Examples.hs
+++ b/src/Core/Examples.hs
@@ -118,6 +118,10 @@ corePrelude = Module (Just ("Prelude", [])) $
         twice f x = f (f x);
         fst p = casePair# p k;
         snd p = casePair# p k1;
+        head l = caseList# l abort# k;
+        tail l = caseList# l abort# k1;
+        _length_cc x xs = (+#) 1 (length xs);
+        length l = caseList# l 0 length_cc;
     |]
     <>
     -- primitive constructors need some specialised wiring:
diff --git a/src/TIM.hs b/src/TIM.hs
index 47a92b5..87bb36b 100644
--- a/src/TIM.hs
+++ b/src/TIM.hs
@@ -49,6 +49,7 @@ data Prim = ConP Int Int -- ConP Tag Arity
           | IntEqP
           | CasePairP
           | CaseListP
+          | AbortP
           deriving (Show, Eq)
 
 instance Pretty Prim where
@@ -105,6 +106,7 @@ primitives =
     , ("if#",       IfP)
     , ("casePair#", CasePairP)
     , ("caseList#", CaseListP)
+    , ("abort#",    AbortP)
     ]
 
 instantiate :: Expr -> TiHeap -> [(Name, Addr)] -> (TiHeap, Addr)
@@ -335,6 +337,9 @@ step st =
                 rootAddr = s !! a
                 argAddrs = getArgs h s
 
+        primStep _ AbortP (TiState s d h g sts) =
+            error "rl' called abort#!"
+
         dataStep :: Int -> [Addr] -> TiState -> TiState
         dataStep _ _ (TiState [a] (s:d) h g sts) = TiState s d h g sts