diff --git a/haskell-experiments/src/Datalog/DatalogDB.hs b/haskell-experiments/src/Datalog/DatalogDB.hs
index 5f7aaa2..1d07f68 100644
--- a/haskell-experiments/src/Datalog/DatalogDB.hs
+++ b/haskell-experiments/src/Datalog/DatalogDB.hs
@@ -23,4 +23,5 @@ class DatalogDB db where
   emptyDB :: db
   lookupRelation :: db -> Text -> Maybe Relation
   insertRelation :: db -> Relation -> db
-  addRule :: (Literal, [Literal]) -> db -> db
\ No newline at end of file
+  addRule :: (Literal, [Literal]) -> db -> db
+  addConstants :: db -> Set Constant -> db
\ No newline at end of file
diff --git a/haskell-experiments/src/Datalog/NaiveDatabase.hs b/haskell-experiments/src/Datalog/NaiveDatabase.hs
index ef38eb2..c62e07b 100644
--- a/haskell-experiments/src/Datalog/NaiveDatabase.hs
+++ b/haskell-experiments/src/Datalog/NaiveDatabase.hs
@@ -63,6 +63,12 @@ instance DatalogDB NaiveDatabase where
       relationMap' = Map.insert relationName relation' relationMap
       constants' = constants db'
 
+  addConstants :: NaiveDatabase -> Set Constant -> NaiveDatabase
+  addConstants db newConstants =
+    db {
+      constants = Set.union newConstants (constants db)
+    }
+
 lookupRelation0 :: DatalogDB db => Text -> db -> Int -> Set [Constant] -> Relation
 lookupRelation0 relationName db newArity tuples =
   case lookupRelation db relationName of
@@ -139,6 +145,7 @@ digestHead db relation (Literal neg relationName terms) =
   headTermToElement (Var name) = 
     RuleElementVariable $ lookupVariable name variableNames
   headTermToElement constant = RuleElementConstant constant
+  -- db' = insertRelation db relation
   relationMap :: Map RelationId Relation = relations db
   relationMap' = Map.insert relationName relation relationMap
   extraVariables = headTermToElement <$> terms