<s>
The	O
drinker	B-Algorithm
paradox	I-Algorithm
(	O
also	O
known	O
as	O
the	O
drinker	O
's	O
theorem	O
,	O
the	O
drinker	B-Algorithm
's	I-Algorithm
principle	I-Algorithm
,	O
or	O
the	B-Algorithm
drinking	I-Algorithm
principle	I-Algorithm
)	O
is	O
a	O
theorem	O
of	O
classical	O
predicate	B-Algorithm
logic	O
that	O
can	O
be	O
stated	O
as	O
"	O
There	O
is	O
someone	O
in	O
the	O
pub	O
such	O
that	O
,	O
if	O
he	O
or	O
she	O
is	O
drinking	O
,	O
then	O
everyone	O
in	O
the	O
pub	O
is	O
drinking.	O
"	O
</s>
<s>
It	O
was	O
popularised	O
by	O
the	O
mathematical	O
logician	O
Raymond	O
Smullyan	O
,	O
who	O
called	O
it	O
the	O
"	O
drinking	B-Algorithm
principle	I-Algorithm
"	O
in	O
his	O
1978	O
book	O
What	O
Is	O
the	O
Name	O
of	O
this	O
Book	O
?	O
</s>
<s>
where	O
D	O
is	O
an	O
arbitrary	O
predicate	B-Algorithm
and	O
P	O
is	O
an	O
arbitrary	O
nonempty	O
set	O
.	O
</s>
<s>
The	O
paradox	B-Application
is	O
ultimately	O
based	O
on	O
the	O
principle	O
of	O
formal	O
logic	O
that	O
the	O
statement	O
is	O
true	O
whenever	O
A	O
is	O
false	O
,	O
i.e.	O
,	O
any	O
statement	O
follows	O
from	O
a	O
false	O
statement	O
(	O
ex	O
falso	O
quodlibet	O
)	O
.	O
</s>
<s>
What	O
is	O
important	O
to	O
the	O
paradox	B-Application
is	O
that	O
the	O
conditional	O
in	O
classical	O
(	O
and	O
intuitionistic	O
)	O
logic	O
is	O
the	O
material	O
conditional	O
.	O
</s>
<s>
Smullyan	O
in	O
his	O
1978	O
book	O
attributes	O
the	O
naming	O
of	O
"	O
The	B-Algorithm
Drinking	I-Algorithm
Principle	I-Algorithm
"	O
to	O
his	O
graduate	O
students	O
.	O
</s>
<s>
He	O
also	O
discusses	O
variants	O
(	O
obtained	O
by	O
replacing	O
D	O
with	O
other	O
,	O
more	O
dramatic	O
predicates	B-Algorithm
)	O
:	O
</s>
<s>
As	O
"	O
Smullyan	O
's	O
‘	O
Drinkers’	O
principle	O
"	O
or	O
just	O
"	O
Drinkers	B-Algorithm
 '	I-Algorithm
principle	I-Algorithm
"	O
it	O
appears	O
in	O
H.P.	O
</s>
<s>
In	O
the	O
setting	O
with	O
empty	O
domains	O
allowed	O
,	O
the	O
drinker	B-Algorithm
paradox	I-Algorithm
must	O
be	O
formulated	O
as	O
follows	O
:	O
</s>
