<s>
The	O
Larch	B-Language
family	I-Language
of	O
formal	B-Application
specification	I-Application
languages	I-Application
are	O
intended	O
for	O
the	O
precise	O
specification	O
of	O
computing	O
systems	O
.	O
</s>
<s>
They	O
allow	O
the	O
clean	O
specification	O
of	O
computer	B-Application
programs	I-Application
and	O
the	O
formulation	O
of	O
proofs	O
about	O
program	O
behavior	O
.	O
</s>
<s>
The	O
Larch	B-Language
family	I-Language
was	O
developed	O
primarily	O
in	O
the	O
United	O
States	O
in	O
the	O
1980s	O
and	O
1990s	O
,	O
involving	O
researchers	O
at	O
Xerox	O
PARC	O
,	O
DEC	O
Systems	O
Research	O
Center	O
(	O
DEC/SRC	O
)	O
,	O
Massachusetts	O
Institute	O
of	O
Technology	O
(	O
MIT	O
)	O
,	O
and	O
other	O
places	O
.	O
</s>
<s>
Unlike	O
the	O
Z	B-Language
notation	I-Language
,	O
the	O
Larch	B-Language
family	I-Language
has	O
one	O
language	O
for	O
algebraic	B-Application
specification	I-Application
of	O
abstract	O
data	O
types	O
(	O
the	O
Larch	B-Language
Shared	I-Language
Language	I-Language
(	O
LSL	O
)	O
)	O
,	O
and	O
a	O
separate	O
interface	O
language	O
tailored	O
to	O
each	O
language	O
in	O
which	O
programs	O
are	O
to	O
be	O
written	O
,	O
such	O
as	O
C	B-Language
,	O
Modula-3	B-Language
,	O
Smalltalk	B-Application
,	O
etc	O
.	O
</s>
<s>
The	O
Larch	O
project	O
also	O
developed	O
tools	O
to	O
support	O
the	O
use	O
of	O
formal	O
specifications	O
,	O
including	O
the	O
Larch	B-Application
Prover	I-Application
(	O
LP	O
)	O
.	O
</s>
