<s>
In	O
the	O
analysis	B-General_Concept
of	I-General_Concept
algorithms	I-General_Concept
,	O
an	O
enumeration	B-Algorithm
algorithm	I-Algorithm
(	O
i.e.	O
,	O
an	O
algorithm	O
for	O
listing	O
a	O
large	O
or	O
infinite	O
collection	O
of	O
structures	O
)	O
is	O
said	O
to	O
have	O
polynomial	B-General_Concept
delay	I-General_Concept
if	O
the	O
time	O
between	O
the	O
output	O
of	O
any	O
one	O
structure	O
and	O
the	O
next	O
is	O
bounded	O
by	O
a	O
polynomial	O
function	O
of	O
the	O
input	O
size	O
,	O
in	O
the	O
worst	B-General_Concept
case	I-General_Concept
.	O
</s>
<s>
Polynomial	B-General_Concept
delay	I-General_Concept
implies	O
that	O
the	O
total	O
time	O
used	O
by	O
an	O
algorithm	O
will	O
be	O
polynomial	O
per	O
output	O
item	O
,	O
but	O
is	O
a	O
stronger	O
requirement	O
.	O
</s>
<s>
In	O
particular	O
,	O
an	O
algorithm	O
with	O
polynomial	B-General_Concept
delay	I-General_Concept
cannot	O
have	O
a	O
startup	O
phase	O
that	O
takes	O
exponential	O
time	O
before	O
it	O
produces	O
a	O
single	O
output	O
,	O
unlike	O
some	O
algorithms	O
that	O
take	O
polynomial	O
time	O
per	O
output	O
item	O
.	O
</s>
<s>
The	O
notion	O
of	O
polynomial	B-General_Concept
delay	I-General_Concept
was	O
first	O
introduced	O
by	O
David	O
S	O
.	O
Johnson	O
,	O
Mihalis	O
Yannakakis	O
and	O
Christos	O
Papadimitriou	O
.	O
</s>
