diff --git a/src/lib/CoAlgMisc.ml b/src/lib/CoAlgMisc.ml
index 00174a7c1a4c4a9518f6ab32158a486331613bbb..4ed6e8843a8e086ddaac23375205f09fbec55e4a 100644
--- a/src/lib/CoAlgMisc.ml
+++ b/src/lib/CoAlgMisc.ml
@@ -165,6 +165,8 @@ type formulaType =
   | NormnF (* negation normal form of default implication *)
   | ChcF (* Choice *)
   | FusF (* Fusion *)
+  | MuF
+  | NuF
 
 type localFormula = int
 type bset = S.bitset
diff --git a/src/lib/CoAlgMisc.mli b/src/lib/CoAlgMisc.mli
index b248c1803ae99d5a4f41a70706d765ed5399acaa..0cb2b18ef432bd6493eba9e4f6b142e58b6b5263 100644
--- a/src/lib/CoAlgMisc.mli
+++ b/src/lib/CoAlgMisc.mli
@@ -52,6 +52,8 @@ type formulaType =
   | NormnF (* negation normal form of default implication *)
   | ChcF
   | FusF
+  | MuF
+  | NuF
 
 type localFormula
 type bset