<s>
Concurrent	B-Application
logic	I-Application
programming	I-Application
is	O
a	O
variant	O
of	O
logic	B-Language
programming	I-Language
in	O
which	O
programs	O
are	O
sets	O
of	O
guarded	O
Horn	B-Application
clauses	I-Application
of	O
the	O
form	O
:	O
</s>
<s>
The	O
conjunction	O
is	O
called	O
the	O
guard	B-Language
of	O
the	O
clause	O
,	O
and	O
is	O
the	O
commitment	O
operator	O
.	O
</s>
<s>
Declaratively	O
,	O
guarded	O
Horn	B-Application
clauses	I-Application
are	O
read	O
as	O
ordinary	O
logical	O
implications	O
:	O
</s>
<s>
The	O
first	O
concurrent	B-Application
logic	I-Application
programming	I-Application
language	O
was	O
the	O
Relational	O
Language	O
of	O
Clark	O
and	O
Gregory	O
,	O
which	O
was	O
an	O
offshoot	O
of	O
IC-Prolog	O
.	O
</s>
<s>
Later	O
versions	O
of	O
concurrent	B-Application
logic	I-Application
programming	I-Application
include	O
Shapiro	O
's	O
Concurrent	O
Prolog	O
and	O
Ueda	O
's	O
Guarded	O
Horn	B-Application
Clause	I-Application
language	O
.	O
</s>
<s>
The	O
development	O
of	O
concurrent	B-Application
logic	I-Application
programming	I-Application
was	O
given	O
an	O
impetus	O
when	O
GHC	O
was	O
used	O
to	O
implement	O
KL1	B-Language
,	O
the	O
systems	O
programming	O
language	O
of	O
the	O
Japanese	O
Fifth	B-Device
Generation	I-Device
Project	I-Device
(	O
FGCS	O
)	O
.	O
</s>
<s>
The	O
choice	O
of	O
concurrent	B-Application
logic	I-Application
programming	I-Application
as	O
the	O
“	O
missing	O
link	O
”	O
between	O
the	O
hardware	O
and	O
the	O
applications	O
was	O
influenced	O
by	O
a	O
visit	O
to	O
the	O
FGCS	O
Project	O
in	O
1982	O
by	O
Ehud	O
Shapiro	O
,	O
who	O
invented	O
Concurrent	O
Prolog	O
.	O
</s>
