<s>
A	O
supercombinator	B-Application
is	O
a	O
mathematical	O
expression	O
which	O
is	O
fully	O
bound	O
and	O
self-contained	O
.	O
</s>
<s>
It	O
may	O
be	O
either	O
a	O
constant	O
or	O
a	O
combinator	B-Application
where	O
all	O
the	O
subexpressions	O
are	O
supercombinators	B-Application
.	O
</s>
<s>
Supercombinators	B-Application
are	O
used	O
in	O
the	O
implementation	O
of	O
functional	O
languages	O
.	O
</s>
<s>
In	O
mathematical	O
terms	O
,	O
a	O
lambda	B-Language
expression	I-Language
S	O
is	O
a	O
supercombinator	B-Application
of	O
arity	O
n	O
if	O
it	O
has	O
no	O
free	O
variables	O
and	O
is	O
of	O
the	O
form	O
λx2	O
...	O
λxn	O
(	O
with	O
n≥0	O
,	O
so	O
that	O
lambdas	O
are	O
not	O
required	O
)	O
such	O
that	O
E	O
itself	O
is	O
not	O
a	O
lambda	B-Language
abstraction	I-Language
and	O
any	O
lambda	B-Language
abstraction	I-Language
in	O
E	O
is	O
again	O
a	O
supercombinator	B-Application
.	O
</s>
