Link pairs of identical numbers so that each number represents the number of cells on the link, including the cells with the numbers. Cells containing 1 represent paths that are 1-cell long. Paths must follow horizontal or vertical directions and are not allowed to cross or overlap other paths.
(Rules and example from WPC 2017 IB)
- Sum Numberlink from WPC 2016/Round 14 was a Number Net puzzle with an additional constraint of a path not occupying 2x2 cells. As the name suggests this is probably sought to be a variant of Arukone but is much closer to Number Net in terms of the ruleset.
History of the puzzle
According to Conceptis Ltd, the puzzle was invented by one editor of the Byakuya Shobo publishing company.  When did this happen is uncertain, but probably in the late 1990s on お絵かきパズルランド (Oekaki Puzzle Land) magazine, first published in 1995.
Most commonly this puzzle is known as Link-a-Pix (a name by Conceptis), but the name of this article is based on the original name given by Byakuya Shobo, ナンバーネットロジック (Number Net Logic).
Appearances in the past WPCs
- WPC 2017/Round 17 by by Rohan Rao
- WPC 2016/Round 14 (part of a Permaculture hybrid) by Matúš Demiger
- WPC 2013/Part 8