<s>
A	O
synchronous	B-Language
programming	I-Language
language	I-Language
is	O
a	O
computer	O
programming	O
language	O
optimized	O
for	O
programming	O
reactive	O
systems	O
.	O
</s>
<s>
For	O
this	O
reason	O
they	O
are	O
often	O
also	O
called	O
real-time	B-General_Concept
systems	I-General_Concept
,	O
and	O
are	O
found	O
often	O
in	O
embedded	B-Architecture
systems	I-Architecture
.	O
</s>
<s>
Synchronous	B-Language
programming	I-Language
(	O
also	O
synchronous	B-Language
reactive	I-Language
programming	I-Language
or	O
SRP	O
)	O
is	O
a	O
computer	O
programming	O
paradigm	O
supported	O
by	O
synchronous	B-Language
programming	I-Language
languages	I-Language
.	O
</s>
<s>
Each	O
gate	O
of	O
the	O
circuit	O
(	O
or	O
,	O
and	O
,	O
...	O
)	O
is	O
therefore	O
assumed	O
to	O
compute	O
its	O
result	O
instantaneously	O
,	O
each	O
wire	O
is	O
assumed	O
to	O
transmit	O
its	O
signal	B-Application
instantaneously	O
.	O
</s>
<s>
The	O
first	O
synchronous	B-Language
programming	I-Language
languages	I-Language
were	O
invented	O
in	O
France	O
in	O
the	O
1980s	O
:	O
Esterel	B-Language
,	O
Lustre	B-Application
and	O
Signal	B-Application
.	O
</s>
<s>
To	O
take	O
a	O
concrete	O
example	O
,	O
the	O
Esterel	B-Language
statement	O
"	O
every	O
60	O
second	O
emit	O
minute	O
"	O
specifies	O
that	O
the	O
signal	B-Application
"	O
minute	O
"	O
is	O
exactly	O
synchronous	O
with	O
the	O
60-th	O
occurrence	O
of	O
the	O
signal	B-Application
"	O
second	O
"	O
.	O
</s>
<s>
This	O
allows	O
deterministic	O
semantics	O
,	O
therefore	O
making	O
synchronous	O
programs	O
amenable	O
to	O
formal	O
analysis	O
,	O
verification	O
and	O
certified	O
code	O
generation	O
,	O
and	O
usable	O
as	O
formal	B-Application
specification	I-Application
formalisms	O
.	O
</s>
