This ticket implements differentiable curves in real differentiable manifolds. This is a follow-up of #19092 within the SageManifolds project (see the metaticket #18528 for an overview).

This ticket implements the following Python classes:

• the parent class OpenInterval for open intervals of R as 1-dimensional diff. manifolds
  with a canonical chart,
  • the subclass RealLine for R as a 1-dimensional diff. manifold
• the parent class DifferentiableCurveSet for homsets Hom(I,M), i.e. sets of differentiable maps
  I --> M, where I is an open interval of R and M a differentiable manifold over R
• the element class DifferentiableCurve for curves, i.e. differentiable maps I --> M

Documentation:
The reference manual is produced by
sage -docbuild reference/manifolds html
It can also be accessed online at http://sagemanifolds.obspm.fr/doc/19124/reference/manifolds/
More documentation (e.g. example worksheets) can be found here.

Depends on #20771

Component: geometry

Keywords: differentiable manifold, curve, interval, real line

Author: Eric Gourgoulhon

Branch/Commit: d3f3798

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/19124