1 files changed, 5 insertions, 0 deletions
diff --git a/src/iflow.sig b/src/iflow.sig
index bc481022..f85322ef 100644
--- a/src/iflow.sig
+++ b/src/iflow.sig
@@ -42,6 +42,11 @@ signature IFLOW = sig
              Known
            | Sql of string
            | Eq
+           | Ne
+           | Lt
+           | Le
+           | Gt
+           | Ge
 
     datatype prop =
              True