New articles section

[fpnc]

For administrative reasons, some documentation that was available at http://acm.uva.es/problemset has moved to this board. To make a clear separation between general posts and this information, it has been placed in a new section called "Articles" that you can find in the header (next to Watched Topics and FAQ).

If you want, you can collaborate posting comments in the subjects already written, so other people can learn with your help. As this new section is like a "library" or "knowledge base", we reserve our right to delete or fuse comments in order to simplify and mantain things in order.