<s>
ISBL	B-Language
(	O
Information	B-Language
Systems	I-Language
Base	I-Language
Language	I-Language
)	O
is	O
the	O
relational	B-Algorithm
algebra	I-Algorithm
notation	O
that	O
was	O
invented	O
for	O
PRTV	B-Application
,	O
one	O
of	O
the	O
earliest	O
database	B-Application
management	I-Application
systems	I-Application
to	O
implement	O
E.F.	O
Codd	O
's	O
relational	B-Architecture
model	I-Architecture
of	O
data	O
.	O
</s>
