feat(algebra/ordered_ring): `a + 1 ≤ 2 * a` (#7995)
feat(algebra/ordered_ring): `a + 1 ≤ 2 * a` (#7995)

Prove one lemma, useful for the Liouville PR #4301.  The placement of the lemma will change, once the `ordered` refactor will get to  `ordered_ring`.





leanprover-community/mathlib,leanprover-community/mathlib