Principia Mathematica.7z.004 -

: Use a utility like 7-Zip or WinRAR to open the first file (.001), which will then automatically stitch the remaining parts together.

: You must have parts .001, .002, .003, and any subsequent parts in the same folder. Principia Mathematica.7z.004

: The work was a massive effort to prove that all of mathematics could be reduced to a system of formal logic. It famously takes over 300 pages just to rigorously prove that : Use a utility like 7-Zip or WinRAR