Using interval arithmetic and interval analysis, constraint solving can be extended to continuous problems. This seems first to have been done in the 80s by extending Prolog. As you say, most constraint software does not do this, but I vouch that it both exists and works!
I wrote a relational interval constraint solver for automated CAD design. It used constraints to eliminate infeasible regions of a design space before a nonlinear solver would generate the actual geometry. It was pretty fun puzzling out how to build this thing!
I wrote a relational interval constraint solver for automated CAD design. It used constraints to eliminate infeasible regions of a design space before a nonlinear solver would generate the actual geometry. It was pretty fun puzzling out how to build this thing!