<s>
In	O
computer	B-General_Concept
science	I-General_Concept
,	O
syntactic	B-Application
closures	I-Application
are	O
an	O
implementation	O
strategy	O
for	O
a	O
hygienic	B-Application
macro	I-Application
system	O
.	O
</s>
<s>
The	O
term	O
pertains	O
to	O
the	O
Scheme	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
When	O
a	O
syntactic	B-Application
closure	I-Application
is	O
used	O
the	O
arguments	O
to	O
a	O
macro	O
call	O
are	O
enclosed	B-Language
in	O
the	O
current	O
environment	O
,	O
such	O
that	O
they	O
cannot	O
inadvertently	O
reference	O
bindings	O
introduced	O
by	O
the	O
macro	O
itself	O
.	O
</s>
