src/HOL/Tools/Quotient/quotient_term.ML

              if Pattern.matches thy (rtrm', rtrm)
              then rtrm else term_mismatch "regularize(constant mismatch)" ctxt rtrm qtrm
            end
        end
 
-  | (((t1 as Const (@{const_name split}, _)) $ Abs (v1, ty, Abs(v1', ty', s1))),
-     ((t2 as Const (@{const_name split}, _)) $ Abs (v2, _ , Abs(v2', _  , s2)))) =>
+  | (((t1 as Const (@{const_name prod_case}, _)) $ Abs (v1, ty, Abs(v1', ty', s1))),
+     ((t2 as Const (@{const_name prod_case}, _)) $ Abs (v2, _ , Abs(v2', _  , s2)))) =>
        regularize_trm ctxt (t1, t2) $ Abs (v1, ty, Abs (v1', ty', regularize_trm ctxt (s1, s2)))
 
-  | (((t1 as Const (@{const_name split}, _)) $ Abs (v1, ty, s1)),
-     ((t2 as Const (@{const_name split}, _)) $ Abs (v2, _ , s2))) =>
+  | (((t1 as Const (@{const_name prod_case}, _)) $ Abs (v1, ty, s1)),
+     ((t2 as Const (@{const_name prod_case}, _)) $ Abs (v2, _ , s2))) =>
        regularize_trm ctxt (t1, t2) $ Abs (v1, ty, regularize_trm ctxt (s1, s2))
 
   | (t1 $ t2, t1' $ t2') =>
        regularize_trm ctxt (t1, t1') $ regularize_trm ctxt (t2, t2')