sage: (QQ^2).submodule([[1,1]])
Vector space of degree 2 and dimension 1 over Rational Field
Basis matrix:
[1 1]
sage: _.category()
Category of finite dimensional vector spaces with basis over (number fields and quotient fields and metric spaces)

Subobjects is missing, so the standard methods ambient, lift, retract are missing.

This is in contrast to CombinatorialFreeModule.

(There is a class-specific method ambient_module though.)

Also there is an apparent conflict of the element method lift with the one defined in free_module_element.pyx; not resolved here.

CC: @tscrim @louisng114

Component: linear algebra

Author: Matthias Koeppe

Branch/Commit: 62f28a3

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/33431