<s>
Protel	B-Language
stands	O
for	O
"	O
Procedure	O
Oriented	O
Type	O
Enforcing	O
Language	O
"	O
.	O
</s>
<s>
It	O
is	O
a	O
programming	O
language	O
created	O
by	O
Nortel	O
Networks	O
and	O
used	O
on	O
telecommunications	O
switching	O
systems	O
such	O
as	O
the	O
DMS-100	B-Protocol
.	O
</s>
<s>
Protel-2	O
is	O
the	O
object-oriented	O
version	O
of	O
Protel	B-Language
.	O
</s>
<s>
The	O
PROTEL	B-Language
language	O
was	O
designed	O
to	O
meet	O
the	O
needs	O
of	O
digital	O
telephony	O
and	O
is	O
the	O
basis	O
of	O
the	O
DMS-100	B-Protocol
line	O
of	O
switching	O
systems	O
PROTEL	B-Language
is	O
a	O
strongly	O
typed	O
,	O
block-structured	O
language	O
which	O
is	O
based	O
heavily	O
on	O
PASCAL	B-Application
and	O
ALGOL	B-Language
68	I-Language
with	O
left-to-right	O
style	O
of	O
variable	O
assignment	O
,	O
variable-sized	O
arrays	O
,	O
and	O
extensible	O
structures	O
.	O
</s>
<s>
The	O
designers	O
of	O
PROTEL	B-Language
significantly	O
extended	O
PASCAL	B-Application
of	O
the	O
day	O
by	O
adding	O
external	O
compilation	O
and	O
extending	O
the	O
data	O
structures	O
available	O
in	O
the	O
language	O
.	O
</s>
<s>
The	O
PROTEL	B-Language
compiler	O
is	O
tightly	O
integrated	O
with	O
the	O
operating	O
system	O
(	O
SOS	O
)	O
,	O
application	O
(	O
CALLP	O
)	O
,	O
the	O
development	O
environment	O
(	O
PLS	O
)	O
and	O
originally	O
the	O
processor	O
(	O
NT40	O
)	O
.	O
</s>
<s>
PLS	O
,	O
SOS	O
,	O
CALLP	O
and	O
the	O
compiler	O
itself	O
are	O
all	O
written	O
in	O
PROTEL	B-Language
.	O
</s>
<s>
Any	O
description	O
of	O
the	O
PROTEL	B-Language
language	O
ca	O
n't	O
help	O
but	O
include	O
some	O
aspects	O
of	O
the	O
other	O
components	O
.	O
</s>
<s>
PROTEL	B-Language
is	O
considered	O
'	O
wordy	O
 '	O
,	O
containing	O
a	O
large	O
number	O
of	O
reserved	O
words	O
with	O
some	O
statements	O
reading	O
like	O
English	O
.	O
</s>
<s>
PROTEL	B-Language
source	O
code	O
is	O
case	O
insensitive	O
but	O
by	O
convention	O
upper	O
case	O
is	O
used	O
for	O
reserved	O
words	O
.	O
</s>
<s>
Block	O
scope	O
is	O
defined	O
by	O
BLOCK	O
and	O
ENDBLOCK	O
statements	O
,	O
which	O
are	O
analogous	O
to	O
BEGIN	O
END	O
in	O
Pascal	B-Application
or	O
{	O
}	O
in	O
C	O
.	O
</s>
<s>
It	O
is	O
declared	O
and	O
used	O
in	O
a	O
manner	O
similar	O
to	O
Pascal-descended	O
languages	O
.	O
</s>
<s>
The	O
modular	O
nature	O
of	O
PROTEL	B-Language
allows	O
relatively	O
small	O
chunks	O
of	O
code	O
to	O
be	O
swapped	O
into	O
a	O
load	O
;	O
if	O
AREAs	O
were	O
planned	O
smartly	O
,	O
this	O
would	O
not	O
affect	O
the	O
placement	O
of	O
modules	O
in	O
memory	O
,	O
thereby	O
avoiding	O
a	O
restart	O
.	O
</s>
