Editing Jordan curve theorem (section)

==== Steinhaus chessboard theorem ====
The [[Steinhaus chessboard theorem]] in some sense shows that the 4-neighbor grid and the 8-neighbor grid "together" implies the Jordan curve theorem, and the 6-neighbor grid is a precise interpolation between them.<ref>{{Cite journal |last=Šlapal |first=J |date=April 2004 |title=A digital analogue of the Jordan curve theorem |journal=Discrete Applied Mathematics |volume=139 |issue=1–3 |pages=231–251 |doi=10.1016/j.dam.2002.11.003 |issn=0166-218X|doi-access=free }}</ref><ref>{{cite journal
 | last = Surówka | first = Wojciech
 | issue = 7
 | journal = Annales Mathematicae Silesianae
 | mr = 1271184
 | pages = 57–61
 | title = A discrete form of Jordan curve theorem
 | url = https://rebus.us.edu.pl/handle/20.500.12128/14250
 | year = 1993}}</ref>

The theorem states that: suppose you put bombs on some squares on a <math>n\times n</math> chessboard, so that a king cannot move from the bottom side to the top side without stepping on a bomb, then a rook can move from the left side to the right side stepping only on bombs.