169,171c169,175
< 	Standard_Real d1 = AV1.Y () * AV2.Z () - AV1.Z () * AV2.Y ();
< 	Standard_Real d2 = AV1.Z () * AV2.X () - AV1.X () * AV2.Z ();
< 	Standard_Real d3 = AV1.X () * AV2.Y () - AV1.Y () * AV2.X ();
---
> Standard_Real Result;
> 
> 	Result	= (AV1.Y () * AV2.Z () - AV1.Z () * AV2.Y ())
> 		- (AV1.X () * AV2.Z () - AV1.Z () * AV2.X ())
> 		- (AV1.X () * AV2.Y () - AV1.Y () * AV2.X ());
> 
> 	return (Abs (Result) <= Graphic3d_Vector_MyEpsilon);
173,174d176
< 	Standard_Boolean res = (Abs (d1) <= Graphic3d_Vector_MyEpsilon) &&  (Abs (d2) <= Graphic3d_Vector_MyEpsilon) &&  (Abs (d3) <= Graphic3d_Vector_MyEpsilon);
< 	return res;