Hi Mateusz. I'll copy-paste what I wrote 4 years ago, and what is still a good description of Alvarado2510's contributions:
"the point is that we're here looking at a copy from the maps of the National Geographic Institute, reverse engingeered as if interpreting a textual description, and if the textual description says that the border follows the river, then the river is made to follow the border, to its extreme consequences"
Alvarado2510 copies from Tommy Guardia maps, and says he's reading the law.