<s>
The	O
Maude	B-Language
system	I-Language
is	O
an	O
implementation	O
of	O
rewriting	O
logic	O
.	O
</s>
<s>
It	O
is	O
similar	O
in	O
its	O
general	O
approach	O
to	O
Joseph	O
Goguen	O
's	O
OBJ3	O
implementation	O
of	O
equational	O
logic	O
,	O
but	O
based	O
on	O
rewriting	O
logic	O
rather	O
than	O
order-sorted	O
equational	O
logic	O
,	O
and	O
with	O
a	O
heavy	O
emphasis	O
on	O
powerful	O
metaprogramming	B-Application
based	O
on	O
reflection	B-Language
.	O
</s>
<s>
Maude	O
sets	O
out	O
to	O
solve	O
a	O
different	O
set	O
of	O
problems	O
than	O
ordinary	O
imperative	O
languages	O
like	O
C	B-Language
,	O
Java	B-Language
or	O
Perl	B-Language
.	O
</s>
<s>
The	O
rules	O
are	O
applied	O
at	O
"	O
random	O
"	O
by	O
the	O
Maude	B-Language
system	I-Language
,	O
meaning	O
that	O
you	O
can	O
not	O
be	O
sure	O
that	O
one	O
rule	O
is	O
applied	O
before	O
another	O
rule	O
and	O
so	O
on	O
.	O
</s>
<s>
Maude	O
has	O
the	O
ability	O
to	O
control	O
what	O
rule	O
applications	O
should	O
be	O
attempted	O
at	O
each	O
step	O
using	O
meta-programming	B-Application
,	O
due	O
to	O
the	O
reflective	O
property	O
or	O
rewriting	O
logic	O
.	O
</s>
<s>
The	O
Maude	B-Language
system	I-Language
has	O
proved	O
flaws	O
in	O
cryptography	O
protocols	O
by	O
just	O
specifying	O
what	O
the	O
system	O
can	O
do	O
,	O
and	O
by	O
looking	O
for	O
unwanted	O
situations	O
(	O
states	O
or	O
terms	O
that	O
should	O
not	O
be	O
possible	O
to	O
reach	O
)	O
the	O
protocol	O
can	O
be	O
shown	O
to	O
contain	O
bugs	O
,	O
not	O
programming	O
bugs	O
but	O
situations	O
happen	O
that	O
are	O
hard	O
to	O
predict	O
just	O
by	O
walking	O
down	O
the	O
"	O
happy	O
path	O
"	O
as	O
most	O
developers	O
do	O
.	O
</s>
