Test that check() catches wrong order of elements

Fails --- next commit will tighten test.
diff --git a/example/eigen.ref b/example/eigen.ref
index bac73be..03091cc 100644
--- a/example/eigen.ref
+++ b/example/eigen.ref
@@ -1,3 +1,4 @@
+should_give_NOT_OK = NOT OK
 fixed_r = OK
 fixed_c = OK
 pt_r(fixed_r) = OK