This puzzle is among the very nice offline set of Simon Tatham's "portable puzzles", with the name of "Untangle" [1] [1] https://www.chiark.greenend.org.uk/~sg

This puzzle is among the very nice offline set of Simon Tatham's "portable puzzles", with the name of "Untangle" [1] [1] https://www.chiark.greenend.org.uk/~sgtatham/puzzles/ https://www.chiark.greenend.org.uk/~sgtatham/puzzles/