the other day, I defined a complex path model in OpenMx with a lot of mxPath objects. By accident, I included a duplicate mxPath object, that is, two mxPath objects with same "to" and "from" properties. While making changes to my model, I changed only the first definition not being aware of the later redefinition and it took me a while until I realized that my first definition was overwritten by the second. I think, OpenMx's behavior makes sense and I'd expect redefinitions of paths to overwrite past definitions. It might still be helpful to users if OpenMx checked for duplicate path definitions and gave out a warning. What do you think?