set

set, iso

set, morphism

set, co-morphism

set, span, iso

set, span, morphism

set, span, co-morphism

?? ....

?? as stable n-cat, vs as .... ???? ....

set, iso, iso, iso, ... ??? ....

???? ......

?? as symetric monoidal categories:

set,iso ?? object

set,map ?? cocomm comonoid

set,comap ?? comm monoid

set,(iso class of) span ?? bicomm bimonoid

????? .....