some documentation and renaming to make it more comprehensible
removed some unneeded assumptions from proof steps
We've had this lemma already: replaced ll42 by outside_reduces_domain
nicer formatting: ^-1 → \inv
made statements more readable
comments about development
using nicer notation, which @caminati introduced
single-letter abbreviations of single symbols are hard for me to understand
stripped unnecessary brackets
We don't need this assumption if we do a completely manual "proof -"
single-letter abbreviations of single symbols are hard for me to understand
stripped unnecessary brackets