Synopsis: Returns true if the input is a valid region. Topics: Regions, Paths, Polygons, List Handling See Also: is_region(), is_1region(), is_region_simple() Usage: bool = is_valid_region(region, ...

Thanks for reminding me of that, Steve! That’s a great example to keep in mind. jackjohnson. Jul 26, 2021 17:16; This is a long shot: could MR2400035 (2009b:11007) Jesse Elliott, Ring structures on ...