diff --git a/tests/2xnfs/test69.xnf b/tests/2xnfs/test69.xnf
new file mode 100644
index 0000000..9cfc68b
--- /dev/null
+++ b/tests/2xnfs/test69.xnf
@@ -0,0 +1,3 @@
+p xnf 1 1
+1+1 0
+c UNSAT
diff --git a/tests/2xnfs/test70.xnf b/tests/2xnfs/test70.xnf
new file mode 100644
index 0000000..2ea4902
--- /dev/null
+++ b/tests/2xnfs/test70.xnf
@@ -0,0 +1,3 @@
+p xnf 1 1
+-1+1 0
+c SAT