<s>
In	O
computing	O
TMG	B-Application
(	O
TransMoGrifier	O
)	O
is	O
a	O
recursive	B-Application
descent	I-Application
compiler-compiler	B-Language
developed	O
by	O
Robert	O
M	O
.	O
McClure	O
and	O
presented	O
in	O
1965	O
.	O
</s>
<s>
TMG	B-Application
ran	O
on	O
systems	O
including	O
OS/360	B-Application
and	O
early	O
Unix	B-Operating_System
.	O
</s>
<s>
It	O
was	O
used	O
to	O
build	O
EPL	O
,	O
an	O
early	O
version	O
of	O
PL/I	B-Language
.	O
</s>
<s>
Douglas	O
McIlroy	O
ported	O
TMG	B-Application
to	O
an	O
early	O
version	O
of	O
Unix	B-Operating_System
.	O
</s>
<s>
According	O
to	O
Ken	O
Thompson	O
,	O
McIlroy	O
wrote	O
TMG	B-Application
in	O
TMG	B-Application
on	O
a	O
piece	O
of	O
paper	O
and	O
"	O
decided	O
to	O
give	O
his	O
piece	O
of	O
paper	O
his	O
piece	O
of	O
paper	O
,	O
"	O
hand-compiling	O
assembly	B-Language
language	I-Language
that	O
he	O
entered	O
and	O
assembled	O
on	O
Thompson	O
's	O
Unix	B-Application
system	I-Application
running	O
on	O
PDP-7	B-Device
.	O
</s>
<s>
Thompson	O
used	O
TMG	B-Application
in	O
1970	O
as	O
a	O
tool	O
to	O
offer	O
Fortran	B-Application
,	O
but	O
due	O
to	O
memory	O
limitations	O
of	O
PDP-7	B-Device
ended	O
up	O
creating	O
the	O
B	B-Language
programming	I-Language
language	I-Language
which	O
was	O
much	O
influenced	O
by	O
BCPL	B-Language
.	O
</s>
<s>
The	O
recursive	B-Application
descent	I-Application
algorithm	O
of	O
TMG	B-Application
was	O
studied	O
formally	O
by	O
Alexander	O
Birman	O
and	O
Jeffrey	O
Ullman	O
.	O
</s>
<s>
The	O
formal	O
description	O
of	O
the	O
algorithms	O
was	O
named	O
TMG	B-Application
recognition	O
scheme	O
(	O
or	O
simply	O
TS	O
)	O
.	O
</s>
