<s>
Tefkat	B-Language
is	O
a	O
model	B-Language
transformation	I-Language
language	I-Language
and	O
a	O
model	O
transformation	O
engine	O
.	O
</s>
<s>
The	O
language	O
is	O
based	O
on	O
F-logic	B-Language
and	O
the	O
theory	O
of	O
stratified	O
logic	B-Language
programs	I-Language
.	O
</s>
<s>
The	O
engine	O
is	O
an	O
Eclipse	B-Application
plug-in	O
for	O
the	O
Eclipse	B-Language
Modeling	I-Language
Framework	I-Language
(	O
EMF	O
)	O
.	O
</s>
<s>
Tefkat	B-Language
was	O
one	O
of	O
the	O
sub-projects	O
of	O
the	O
Pegamento	O
project	O
at	O
the	O
Distributed	O
Systems	O
Technology	O
Centre	O
(	O
DSTC	O
)	O
,	O
Australia	O
.	O
</s>
<s>
Although	O
the	O
project	O
was	O
already	O
underway	O
,	O
the	O
most	O
active	O
research	O
occurred	O
for	O
the	O
submission	O
of	O
a	O
response	O
to	O
the	O
OMG	B-Architecture
's	O
MOF	B-Application
2.0	O
Queries	B-Language
/	I-Language
Views	I-Language
/	I-Language
Transformations	I-Language
Request	O
for	O
Proposals	O
.	O
</s>
<s>
Tefkat	B-Language
was	O
open-sourced	O
before	O
the	O
closure	O
of	O
the	O
DSTC	O
in	O
June	O
2006	O
.	O
</s>
<s>
Tefkat	B-Language
defines	O
a	O
mapping	O
from	O
a	O
set	O
of	O
source	O
metamodels	O
to	O
a	O
set	O
of	O
target	O
metamodels	O
.	O
</s>
<s>
A	O
Tefkat	B-Language
transformation	O
consists	O
of	O
rules	O
,	O
patterns	O
and	O
templates	O
.	O
</s>
<s>
These	O
elements	O
are	O
based	O
on	O
F-logic	B-Language
and	O
pure	O
logic	B-Language
programming	I-Language
,	O
however	O
the	O
absence	O
of	O
function	O
symbols	O
means	O
a	O
significant	O
reduction	O
in	O
complexity	O
.	O
</s>
<s>
Tefkat	B-Language
has	O
two	O
more	O
significant	O
language	O
elements	O
:	O
trackings	O
and	O
injections	O
.	O
</s>
<s>
Thus	O
injections	O
are	O
similar	O
(	O
but	O
more	O
powerful	O
)	O
to	O
QVT	B-Language
's	O
keys	O
,	O
which	O
specify	O
a	O
target	O
object	O
's	O
identity	O
to	O
be	O
a	O
function	O
of	O
its	O
type	O
and	O
some	O
of	O
its	O
properties	O
.	O
</s>
<s>
The	O
declarative	O
semantics	O
of	O
a	O
Tefkat	B-Language
transformation	O
is	O
the	O
perfect	O
model	O
of	O
traces	O
and	O
targets	O
that	O
satisfies	O
all	O
the	O
rules	O
.	O
</s>
<s>
A	O
more	O
imperative	O
semantics	O
of	O
a	O
Tefkat	B-Language
transformation	O
is	O
the	O
iterated	O
least	O
fixed-point	O
of	O
the	O
immediate	O
consequence	O
of	O
each	O
rule	O
.	O
</s>
<s>
Tefkat	B-Language
does	O
not	O
use	O
explicit	O
rule-calling	O
;	O
all	O
(	O
non-abstract	O
)	O
rules	O
fire	O
independently	O
from	O
all	O
others	O
,	O
however	O
rules	O
can	O
be	O
loosely	O
coupled	O
using	O
trackings	O
,	O
injections	O
,	O
rule	O
extension	O
and/or	O
rule	O
superseding	O
.	O
</s>
<s>
Tefkat	B-Language
has	O
an	O
SQL-like	O
concrete	O
syntax	O
designed	O
to	O
concisely	O
convey	O
the	O
intent	O
of	O
each	O
rule	O
,	O
pattern	O
or	O
template	O
.	O
</s>
<s>
The	O
Tefkat	B-Language
language	O
is	O
defined	O
in	O
terms	O
of	O
(	O
E	O
)	O
MOF	B-Application
2.0	O
,	O
however	O
the	O
engine	O
is	O
implemented	O
in	O
terms	O
of	O
Ecore	O
,	O
the	O
EMOF-like	O
metametamodel	O
at	O
the	O
centre	O
of	O
EMF	O
.	O
</s>
<s>
The	O
language	O
is	O
very	O
similar	O
to	O
the	O
Relations	O
package	O
of	O
QVT	B-Language
,	O
however	O
it	O
is	O
not	O
strictly	O
compliant	O
.	O
</s>
