This puzzle style was created by Erhard Notz for the 2019 World Puzzle Championship (innovations round). More Equality puzzles will be in our upcoming Loop Variety Collection 2.
or solve online (using our beta test of Penpa-Edit tools; use tab to shift between the default linex mode where left click+drag draws lines and right click marks X’s and a shading mode to help mark cells.)
Author/Opus: This is the 236th puzzle from our contributing puzzlemaster Murat Can Tonta.
Rules: Draw a single, non-intersecting loop in the grid that passes through some of the white cells. Each bold region must be visited at least twice by the loop. Each visit to the same region must pass through the same number of cells. If a number clue is given in a region, that number indicates the number of cells not used by the loop in that region. The loop cannot pass through gray cells, and gray cells cannot be counted as part of any bold region.
Also see this example:
Difficulty: 4 stars
Time Standards (highlight to view): Grandmaster = 5:45, Master = 9:30, Expert = 19:00