<s>
Mace	O
stands	O
for	O
"	O
Models	B-Application
And	I-Application
Counter-Examples	I-Application
"	O
,	O
and	O
is	O
a	O
model	O
finder	O
.	O
</s>
<s>
Most	O
automated	B-Application
theorem	I-Application
provers	I-Application
try	O
to	O
perform	O
a	O
proof	O
by	O
refutation	O
on	O
the	O
clause	B-Application
normal	I-Application
form	I-Application
of	O
the	O
proof	O
problem	O
,	O
by	O
showing	O
that	O
the	O
combination	O
of	O
axioms	B-Algorithm
and	O
negated	O
conjecture	O
can	O
never	O
be	O
simultaneously	O
true	O
,	O
i.e.	O
</s>
<s>
Mace	O
is	O
GNU	B-License
GPL	I-License
licensed	O
.	O
</s>
