Don't create a %permit delta if there is no change.
=/ sus/(set ship)
%. sis.con.shape
?:(add ~(dif in sis) ~(int in sis))
+ ?~ sus +>.$
=. +>.$
%- so-act
:- %phrase
- %- ~(rep in sus)
+ %- ~(rep in `(set ship)`sus)
|= {s/ship a/audience t/(list speech)}
:- (~(put in a) [s %inbox])
[[%inv inv so-cir] t]
