working on proving let
proved some lemmas for let, also does lots of refactoring/renaming.
before change effects2output
added some minor changes
- removed consider-nn
- removed consider-nn from efxmap2perm and make-encumbered.
Turns out I still need conditionals in efxmap2perm and make-encumbered.
in progress
proved first half of let
before switch to capability-based approach
 in progress
now working with read/write (no exists)
exists now work for read
changed capmap-min-cap to capmap-min; code styple change
proved tLit
proving tLet - some lemma needs to be proven
changed ty2perm2 to always use conditional
tLet proved, with loads of trustmes