Blog: Topology
![Rapid introduction to modal logic, part 2](/files/cm/thumb.cmgtl00q.serokell-introdaction-to-modal-logic-part2.jpg)
![Rapid introduction to modal logic, part 2](/files/60/thumb.609egqzu.modal-logic-2.jpg)
Incomplete and Utter Introduction to Modal Logic, Pt. 2
In the first part, we introduced the reader to basic modal logic. In this part of the introduction to the modal logic, we observe use cases and take a look at connections of modal logic with topology, foundations of mathematics, and computer science.
![Insane Properties of the Closed Long Ray and the Long Line](/files/xn/thumb.xnic4lad.Topology.jpg)
![Insane Properties of the Closed Long Ray and the Long Line](/files/2a/thumb.2a34utvk.insane-properties.jpg)
Insane Properties of the Closed Long Ray and the Long Line
In topology, the long line, or Alexandroff line, is a space somewhat similar to the real line, but ‘longer’. To obtain the long line, one needs to put together a long ray in each direction. Closed long rays, as well as long lines, have remarkable properties.