Pavestone2734
The complete regular expression is:
^((?!calendar).)*$
Copy & paste it into Obtainium's input field: “Filter APKs by regular expression”.
This is “the nerd version”. ;-)
Of course it also works as Dumdum has described. ;-)
BTW: I also make it easier for myself with some APKs, e.g. Molly-FOSS:
There are always several versions in the repository and I prefer the FOSS version.
So I just write ‘FOSS’ as a regular expression instead of 100% correct reg ex ;-)