<s>
CGOL	B-Language
(	O
pronounced	O
"	O
see	O
goll	O
"	O
)	O
is	O
an	O
alternative	O
syntax	O
featuring	O
an	O
extensible	O
algebraic	O
notation	O
for	O
the	O
Lisp	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
It	O
was	O
designed	O
for	O
MACLISP	B-Language
by	O
Vaughan	O
Pratt	O
and	O
subsequently	O
ported	O
to	O
Common	B-Language
Lisp	I-Language
.	O
</s>
<s>
The	O
notation	O
of	O
CGOL	B-Language
is	O
a	O
traditional	O
infix	O
notation	O
,	O
in	O
the	O
style	O
of	O
ALGOL	B-Language
,	O
rather	O
than	O
Lisp	B-Language
's	O
traditional	O
,	O
uniformly-parenthesized	O
prefix	O
notation	O
syntax	O
.	O
</s>
<s>
The	O
CGOL	B-Language
parser	B-Language
is	O
based	O
on	O
Pratt	O
's	O
design	O
for	O
top-down	B-Application
operator	B-Application
precedence	I-Application
parsing	B-Language
,	O
sometimes	O
informally	O
referred	O
to	O
as	O
a	O
"	O
Pratt	O
parser	B-Language
"	O
.	O
</s>
<s>
Semantically	O
,	O
CGOL	B-Language
is	O
essentially	O
just	O
Common	B-Language
Lisp	I-Language
,	O
with	O
some	O
additional	O
reader	O
and	O
printer	O
support	O
.	O
</s>
<s>
CGOL	B-Language
may	O
be	O
regarded	O
as	O
a	O
more	O
successful	O
incarnation	O
of	O
some	O
of	O
the	O
essential	O
ideas	O
behind	O
the	O
earlier	O
LISP	B-Language
2	I-Language
project	O
.	O
</s>
<s>
Lisp	B-Language
2	I-Language
was	O
a	O
successor	O
to	O
LISP	B-Language
1.5	I-Language
that	O
aimed	O
to	O
provide	O
ALGOL	B-Language
syntax	O
.	O
</s>
<s>
LISP	B-Language
2	I-Language
was	O
abandoned	O
,	O
whereas	O
it	O
is	O
possible	O
to	O
use	O
the	O
CGOL	B-Language
codebase	O
today	O
.	O
</s>
<s>
This	O
is	O
because	O
unlike	O
LISP	B-Language
2	I-Language
,	O
CGOL	B-Language
is	O
implemented	O
as	O
portable	O
functions	O
and	O
macros	O
written	O
in	O
Lisp	B-Language
,	O
requiring	O
no	O
alterations	O
to	O
the	O
host	O
Lisp	B-Language
implementation	O
.	O
</s>
<s>
Special	O
notations	O
are	O
available	O
for	O
many	O
commonly	O
used	O
Common	B-Language
Lisp	I-Language
operations	O
.	O
</s>
<s>
CGOL	B-Language
has	O
an	O
infix	O
.	O
</s>
<s>
operation	O
(	O
referring	O
to	O
Common	B-Language
Lisp	I-Language
's	O
cons	O
function	O
)	O
and	O
the	O
infix	O
@	O
operation	O
(	O
referring	O
to	O
Common	B-Language
Lisp	I-Language
's	O
append	O
function	O
)	O
:	O
</s>
<s>
The	O
preceding	O
example	O
corresponds	O
to	O
this	O
text	O
in	O
native	O
Common	B-Language
Lisp	I-Language
:	O
</s>
<s>
CGOL	B-Language
uses	O
of	O
to	O
read	O
and	O
set	O
properties	O
:	O
</s>
<s>
The	O
preceding	O
example	O
corresponds	O
to	O
this	O
text	O
in	O
native	O
Common	B-Language
Lisp	I-Language
:	O
</s>
<s>
This	O
illustrates	O
how	O
CGOL	B-Language
notates	O
a	O
function	O
of	O
two	O
arguments	O
:	O
</s>
<s>
The	O
preceding	O
example	O
corresponds	O
to	O
this	O
text	O
in	O
native	O
Common	B-Language
Lisp	I-Language
:	O
</s>
<s>
The	O
syntax	O
of	O
CGOL	B-Language
is	O
data-driven	O
and	O
so	O
both	O
modifiable	O
and	O
extensible	O
.	O
</s>
<s>
CGOL	B-Language
is	O
known	O
to	O
work	O
on	O
Armed	O
Bear	O
Common	B-Language
Lisp	I-Language
.	O
</s>
<s>
The	O
CGOL	B-Language
source	O
code	O
and	O
some	O
text	O
files	O
containing	O
discussions	O
of	O
it	O
are	O
available	O
as	O
freeware	O
from	O
Carnegie-Mellon	O
University	O
's	O
Artificial	O
Intelligence	O
Repository	O
.	O
</s>
