Cache the slot in +slur, which makes the type passed to ~nest the same noun each time.
++ slur :: call gate on
|= {gat/vase hil/mill}
^- (unit (pair vase worm))
- =+ sam=(slot 6 gat)
+ =^ sam p.sew (~(slot wa p.sew) 6 gat)
=+ ^= hig
?- -.hil
%& (~(nest wa p.sew) p.sam p.p.hil)
