diff --git a/IFC4x3/Sections/Core data schemas/Schemas/IfcProductExtension/Functions/IfcAlignmentRepresentation/Expression.txt b/IFC4x3/Sections/Core data schemas/Schemas/IfcProductExtension/Functions/IfcAlignmentRepresentation/Expression.txt
index e6b5d5434..130ebd296 100644
--- a/IFC4x3/Sections/Core data schemas/Schemas/IfcProductExtension/Functions/IfcAlignmentRepresentation/Expression.txt	
+++ b/IFC4x3/Sections/Core data schemas/Schemas/IfcProductExtension/Functions/IfcAlignmentRepresentation/Expression.txt	
@@ -4,8 +4,8 @@
 		AlignmentRepresentations : SET OF IfcShapeRepresentation;
 		TwoDRep : SET OF IfcShapeRepresentation;
 		ThreeDRep : SET OF IfcShapeRepresentation;
-		CurveTwoD : IfcCompositeCurve;
-		CurveThreeD : IfcGradientCurve;
+		CurveTwoD : SET OF IfcCompositeCurve;
+		CurveThreeD : SET OF IfcGradientCurve;
 	END_LOCAL;
 
 	(* no representation is okay *)
@@ -53,7 +53,7 @@
 		ThreeDRep := QUERY(threeDee <* AlignmentRepresentations | threeDee.RepresentationType = 'Curve3D');
 		CurveThreeD := QUERY(item <* ThreeDRep[1].Items | 'IFCGEOMETRYRESOURCE.IFCGRADIENTCURVE' in TYPEOF(item));
 		
-		RETURN((SIZEOF(CurveThreeD) = 1) AND (SIZEOF(CurveTwoD) = 1) AND (CurveThreeD\IfcGradientCurve.BaseCurve :=: CurveTwoD));
+		RETURN((SIZEOF(CurveThreeD) = 1) AND (SIZEOF(CurveTwoD) = 1) AND (CurveThreeD[1].BaseCurve :=: CurveTwoD[1]));
 	
 	END_IF;
 	(* Missing an IFCSEGMENTEDREFERENCECURVE various placement option implementation. *)