<s>
Greenspun	B-Language
's	I-Language
tenth	I-Language
rule	I-Language
of	I-Language
programming	I-Language
is	O
an	O
aphorism	O
in	O
computer	B-General_Concept
programming	I-General_Concept
and	O
especially	O
programming	O
language	O
circles	O
that	O
states	O
:	O
</s>
<s>
The	O
rule	O
expresses	O
the	O
opinion	O
that	O
the	O
argued	O
flexibility	O
and	O
extensibility	B-Architecture
designed	O
into	O
the	O
programming	O
language	O
Lisp	B-Language
includes	O
all	O
functionality	O
that	O
is	O
theoretically	O
needed	O
to	O
write	O
any	O
complex	O
computer	O
program	O
,	O
and	O
that	O
the	O
features	O
required	O
to	O
develop	O
and	O
manage	O
such	O
complexity	O
in	O
other	O
programming	O
languages	O
are	O
equivalent	O
to	O
some	O
subset	O
of	O
the	O
methods	O
used	O
in	O
Lisp	B-Language
.	O
</s>
<s>
Other	O
programming	O
languages	O
,	O
while	O
claiming	O
to	O
be	O
simpler	O
,	O
require	O
programmers	O
to	O
reinvent	O
in	O
a	O
haphazard	O
way	O
a	O
significant	O
amount	O
of	O
needed	O
functionality	O
that	O
is	O
present	O
in	O
Lisp	B-Language
as	O
a	O
standard	O
,	O
time-proven	O
base	O
.	O
</s>
<s>
Rather	O
than	O
including	O
a	O
custom	O
interpreter	B-Application
for	O
some	O
domain-specific	B-Language
language	I-Language
,	O
Greenspun	O
's	O
rule	O
suggests	O
using	O
a	O
widely	O
accepted	O
,	O
fully	O
featured	O
language	O
like	O
Lisp	B-Language
.	O
</s>
<s>
This	O
corollary	O
jokingly	O
refers	O
to	O
the	O
fact	O
that	O
many	O
Common	B-Language
Lisp	I-Language
implementations	O
(	O
especially	O
those	O
available	O
in	O
the	O
early	O
1990s	O
)	O
depend	O
upon	O
a	O
low-level	O
core	O
of	O
compiled	O
C	B-Language
,	O
which	O
sidesteps	O
the	O
issue	O
of	O
bootstrapping	B-Application
but	O
may	O
itself	O
be	O
somewhat	O
variable	O
in	O
quality	O
,	O
at	O
least	O
compared	O
to	O
a	O
cleanly	O
self-hosting	O
Common	B-Language
Lisp	I-Language
.	O
</s>
