Why do you think Sussman et al's. propagator don't solve OP problem?
I don't think Basa was saying this, exactly. I think Basa meant using something like Matt Keeter's project: https://www.mattkeeter.com/projects/ao/ https://www.mattkeeter.com/projects/ao/screencast.html [video] (which is a functional CAD modeling system using C++/Guile) as a backend (graphical kernel) for a propagator network which solves engineering constraints. The reason Basa said it was a ways off is that the propagator code is in MIT Scheme. That would mean either the code for the propagator would have to be ported or the code for Ao would be. Ao itself is a nice project done in Guile, like OpenSCAD using Guile as a language. Another valid issue Basa revisited is that there would probably need to be sandboxing or a declarative language layer to use Ao for security with shared models. This issue was discussed a while back on this mailing list.
