`gsummptres` proved using OpenAI's proof assistant, other theorems
`gsummptres` proved using OpenAI's proof assistant, other theorems

* lemmas for Lambda-Pi theorem
* clean-up of usused ~ gsummptadd
* first step of cleaning up unused `TarskiG2D` (incl. axtglowdim2OLD and axtgupdim2OLD)

metamath/set.mm,metamath/set.mm,metamath/set.mm