<s>
In	O
Boolean	O
logic	O
,	O
a	O
formula	O
for	O
a	O
Boolean	O
function	O
f	O
is	O
in	O
Blake	B-Application
canonical	I-Application
form	I-Application
(	O
BCF	O
)	O
,	O
also	O
called	O
the	O
complete	B-Application
sum	I-Application
of	I-Application
prime	I-Application
implicants	I-Application
,	O
the	O
complete	B-Application
sum	I-Application
,	O
or	O
the	O
disjunctive	B-Application
prime	I-Application
form	I-Application
,	O
when	O
it	O
is	O
a	O
disjunction	O
of	O
all	O
the	O
prime	O
implicants	O
of	O
f	O
.	O
</s>
<s>
The	O
Blake	B-Application
canonical	I-Application
form	I-Application
is	O
a	O
special	O
case	O
of	O
disjunctive	B-Application
normal	I-Application
form	I-Application
.	O
</s>
<s>
The	O
Blake	B-Application
canonical	I-Application
form	I-Application
is	O
not	O
necessarily	O
minimal	O
(	O
upper	O
diagram	O
)	O
,	O
however	O
all	O
the	O
terms	O
of	O
a	O
minimal	O
sum	O
are	O
contained	O
in	O
the	O
Blake	B-Application
canonical	I-Application
form	I-Application
.	O
</s>
<s>
On	O
the	O
other	O
hand	O
,	O
the	O
Blake	B-Application
canonical	I-Application
form	I-Application
is	O
a	O
canonical	O
form	O
,	O
that	O
is	O
,	O
it	O
is	O
unique	O
up	O
to	O
reordering	O
,	O
whereas	O
there	O
can	O
be	O
multiple	O
minimal	O
forms	O
(	O
lower	O
diagram	O
)	O
.	O
</s>
<s>
Selecting	O
a	O
minimal	O
sum	O
from	O
a	O
Blake	B-Application
canonical	I-Application
form	I-Application
amounts	O
in	O
general	O
to	O
solving	O
the	O
set	B-Algorithm
cover	I-Algorithm
problem	I-Algorithm
,	O
so	O
is	O
NP-hard	O
.	O
</s>
<s>
He	O
called	O
it	O
the	O
"	O
simplified	B-Application
canonical	I-Application
form	I-Application
"	O
;	O
it	O
was	O
named	O
the	O
"	O
Blake	B-Application
canonical	I-Application
form	I-Application
"	O
by	O
and	O
in	O
1986	O
–	O
1990	O
.	O
</s>
