<s>
The	O
TREE-META	B-Application
(	O
or	O
Tree	B-Application
Meta	I-Application
,	O
TREEMETA	O
)	O
Translator	O
Writing	O
System	O
is	O
a	O
compiler-compiler	B-Language
system	O
for	O
context-free	O
languages	O
originally	O
developed	O
in	O
the	O
1960s	O
.	O
</s>
<s>
TREE-META	B-Application
was	O
instrumental	O
in	O
the	O
development	O
of	O
NLS	O
(	O
oN-Line	O
System	O
)	O
and	O
was	O
ported	O
to	O
many	O
systems	O
including	O
the	O
UNIVAC	O
1108	O
,	O
GE	B-Device
645	I-Device
,	O
SDS	B-Device
940	I-Device
,	O
ICL	B-Device
1906A	I-Device
,	O
PERQ	B-Device
,	O
and	O
UCSD	B-Language
p-System	I-Language
.	O
</s>
<s>
This	O
is	O
a	O
complete	O
example	O
of	O
a	O
TREE-META	B-Application
program	O
extracted	O
(	O
and	O
untested	O
)	O
from	O
the	O
more	O
complete	O
(	O
declarations	O
,	O
conditionals	O
,	O
and	O
blocks	O
)	O
example	O
in	O
Appendix	O
6	O
of	O
the	O
ICL	B-Device
1900	I-Device
TREE-META	B-Application
manual	O
.	O
</s>
<s>
That	O
document	O
also	O
has	O
a	O
definition	O
of	O
TREE-META	B-Application
in	O
TREE-META	B-Application
in	O
Appendix	O
3	O
.	O
</s>
<s>
This	O
program	O
is	O
not	O
just	O
a	O
recognizer	O
,	O
but	O
also	O
outputs	O
the	O
assembly	B-Language
language	I-Language
for	O
the	O
input	O
.	O
</s>
<s>
It	O
demonstrates	O
one	O
of	O
the	O
key	O
features	O
of	O
TREE-META	B-Application
,	O
which	O
is	O
tree	O
pattern	O
matching	O
.	O
</s>
