2016-03-15 paulson 2016-03-15 rationalisation of theorem names esp about "real Archimedian" etc.
2016-02-19 hoelzl 2016-02-19 generalize more theorems to support enat and ennreal
2016-02-10 hoelzl 2016-02-10 Rename ordered_comm_monoid_add to ordered_cancel_comm_monoid_add. Introduce ordreed_comm_monoid_add, canonically_ordered_comm_monoid and dioid. Setup nat, entat and ennreal as dioids.
2016-02-09 hoelzl 2016-02-09 add extended nonnegative real numbers