<s>
E	B-Language
is	O
a	O
high-performance	O
theorem	B-Application
prover	I-Application
for	O
full	O
first-order	O
logic	O
with	O
equality	O
.	O
</s>
<s>
It	O
has	O
been	O
integrated	O
into	O
other	O
theorem	O
provers	O
and	O
it	O
has	O
been	O
among	O
the	O
best-placed	O
systems	O
in	O
several	O
theorem	B-Application
proving	I-Application
competitions	O
.	O
</s>
<s>
E	B-Language
is	O
developed	O
by	O
Stephan	B-Language
Schulz	I-Language
,	O
originally	O
in	O
the	O
Automated	O
Reasoning	O
Group	O
at	O
TU	O
Munich	O
,	O
now	O
at	O
Baden-Württemberg	O
Cooperative	O
State	O
University	O
Stuttgart	O
.	O
</s>
<s>
Significant	O
innovations	O
include	O
shared	O
term	O
rewriting	O
(	O
where	O
many	O
possible	O
equational	O
simplifications	O
are	O
carried	O
out	O
in	O
a	O
single	O
operation	O
)	O
,	O
several	O
efficient	O
term	B-Application
indexing	I-Application
data	O
structures	O
for	O
speeding	O
up	O
inferences	O
,	O
advanced	O
inference	O
literal	O
selection	O
strategies	O
,	O
and	O
various	O
uses	O
of	O
machine	O
learning	O
techniques	O
to	O
improve	O
the	O
search	O
behaviour	O
.	O
</s>
<s>
Since	O
version	O
2.0	O
,	O
E	B-Language
supports	O
many-sorted	O
logic	O
.	O
</s>
<s>
E	B-Language
is	O
implemented	O
in	O
C	B-Language
and	O
portable	O
to	O
most	O
UNIX	B-Application
variants	O
and	O
the	O
Cygwin	B-Language
environment	O
.	O
</s>
<s>
It	O
is	O
available	O
under	O
the	O
GNU	B-License
GPL	I-License
.	O
</s>
<s>
The	O
prover	O
has	O
consistently	O
performed	O
well	O
in	O
the	O
CADE	B-General_Concept
ATP	I-General_Concept
System	I-General_Concept
Competition	I-General_Concept
,	O
winning	O
the	O
CNF/MIX	O
category	O
in	O
2000	O
and	O
finishing	O
among	O
the	O
top	O
systems	O
ever	O
since	O
.	O
</s>
<s>
In	O
2009	O
it	O
won	O
second	O
place	O
in	O
the	O
FOF	O
(	O
full	O
first	O
order	O
logic	O
)	O
and	O
UEQ	O
(	O
unit	O
equational	O
logic	O
)	O
categories	O
and	O
third	O
place	O
(	O
after	O
two	O
versions	O
of	O
Vampire	O
)	O
in	O
CNF	B-Application
(	O
clausal	O
logic	O
)	O
.	O
</s>
<s>
It	O
repeated	O
the	O
performance	O
in	O
FOF	O
and	O
CNF	B-Application
in	O
2010	O
,	O
and	O
won	O
a	O
special	O
award	O
as	O
"	O
overall	O
best	O
"	O
system	O
.	O
</s>
<s>
In	O
the	O
2011	O
CASC-23	O
E	B-Language
won	O
the	O
CNF	B-Application
division	O
and	O
achieved	O
second	O
places	O
in	O
UEQ	O
and	O
LTB	O
.	O
</s>
<s>
E	B-Language
has	O
been	O
integrated	O
into	O
several	O
other	O
theorem	O
provers	O
.	O
</s>
<s>
It	O
is	O
,	O
with	O
Vampire	O
,	O
SPASS	B-Application
,	O
,	O
and	O
,	O
at	O
the	O
core	O
of	O
Isabelle	B-Application
's	O
Sledgehammer	O
strategy	O
.	O
</s>
<s>
E	B-Language
also	O
is	O
the	O
reasoning	O
engine	O
in	O
SInE	O
and	O
LEO-II	O
and	O
used	O
as	O
the	O
clausification	O
system	O
for	O
iProver	O
.	O
</s>
<s>
Applications	O
of	O
E	B-Language
include	O
reasoning	O
on	O
large	O
ontologies	O
,	O
software	O
verification	O
,	O
and	O
software	O
certification	O
.	O
</s>
