diff --git a/lisa-front/src/main/scala/lisa/front/parser/FrontResolver.scala b/lisa-front/src/main/scala/lisa/front/parser/FrontResolver.scala
index c655652478e1e6db4b97a89287727bd68e128b6e..8ce715c4c5f15c2516f0135c18858fbb4e34de93 100644
--- a/lisa-front/src/main/scala/lisa/front/parser/FrontResolver.scala
+++ b/lisa-front/src/main/scala/lisa/front/parser/FrontResolver.scala
@@ -96,7 +96,7 @@ private[parser] object FrontResolver {
     case operator: ParsedBinaryOperator =>
       val label: Either[PredicateLabel[?], ConnectorLabel[?]] = operator match {
         case _: ParsedEqual => Left(equality)
-        case _: ParsedMembership => Left(ConstantPredicateLabel[2]("set_membership"))
+        case _: ParsedMembership => Left(ConstantPredicateLabel[2]("elem"))
         case _: ParsedSubset => Left(ConstantPredicateLabel[2]("subset_of"))
         case _: ParsedSameCardinality => Left(ConstantPredicateLabel[2]("same_cardinality"))
         case _: ParsedAnd => Right(and)
diff --git a/lisa-theories/src/main/scala/lisa/settheory/SetTheoryDefinitions.scala b/lisa-theories/src/main/scala/lisa/settheory/SetTheoryDefinitions.scala
index 4a9c48923083b6653116b105548b9aa321206cc0..17039b65ba279816470fcd74afb253b9350a1bc2 100644
--- a/lisa-theories/src/main/scala/lisa/settheory/SetTheoryDefinitions.scala
+++ b/lisa-theories/src/main/scala/lisa/settheory/SetTheoryDefinitions.scala
@@ -16,7 +16,7 @@ private[settheory] trait SetTheoryDefinitions {
   /**
    * The symbol for the set membership predicate.
    */
-  final val in = ConstantPredicateLabel("set_membership", 2)
+  final val in = ConstantPredicateLabel("elem", 2)
 
   /**
    * The symbol for the subset predicate.