<s>
is	O
an	O
extension	O
of	O
the	O
concept	O
of	O
catamorphism	B-Application
first	O
introduced	O
by	O
Lambert	O
Meertens	O
to	O
deal	O
with	O
a	O
form	O
which	O
“	O
eats	O
its	O
argument	O
and	O
keeps	O
it	O
too	O
”	O
,	O
</s>
<s>
Its	O
categorical	O
dual	O
is	O
the	O
apomorphism	B-Application
.	O
</s>
<s>
It	O
is	O
a	O
more	O
convenient	O
version	O
of	O
catamorphism	B-Application
in	O
that	O
it	O
gives	O
the	O
combining	O
step	O
function	O
immediate	O
access	O
not	O
only	O
to	O
the	O
result	O
value	O
recursively	O
computed	O
from	O
each	O
recursive	O
subobject	O
,	O
but	O
the	O
original	O
subobject	O
itself	O
as	O
well	O
.	O
</s>
