id summary reporter owner description type status priority milestone component resolution keywords cc merged author reviewer upstream work_issues branch commit dependencies stopgaps
31241 Forgetful Functors for Manifold Objects gh-mjungmath "It would be nice to allow forgetful functors for manifolds. In particular:
- differentiable manifolds -> topological manifolds
- (Pseudo-)Riemannian manifolds -> differentiable manifolds (not a category yet)
- topological manifolds -> sets (?)
and probably even more. The last point, if getting to work somehow, might also be useful and/or should be seen in view of #30832.
At the moment, we have the following behavior (which could be seen as a bug):
{{{
sage: from sage.categories.functor import ForgetfulFunctor
sage: from sage.categories.manifolds import Manifolds
sage: F = ForgetfulFunctor(Manifolds(RR).Differentiable(), Manifolds(RR).Topological())
sage: M = Manifold(2, 'M')
sage: F(M)
2-dimensional differentiable manifold M
}}}
" enhancement new major sage-9.5 manifolds tscrim egourgoulhon mkoeppe N/A #31247