<s>
A	O
suitable	O
discrete	O
subgroup	O
Γ	O
may	O
or	O
may	O
not	O
exist	O
,	O
for	O
a	O
given	O
G	O
and	O
H	O
.	O
If	O
Γ	O
exists	O
,	O
there	O
is	O
the	O
question	O
of	O
whether	O
Γ	O
\G/H	O
can	O
be	O
taken	O
to	O
be	O
a	O
compact	O
space	O
,	O
called	O
a	O
compact	O
Clifford	B-Algorithm
–	I-Algorithm
Klein	I-Algorithm
form	I-Algorithm
.	O
</s>
<s>
When	O
H	O
is	O
itself	O
compact	O
,	O
classical	O
results	O
show	O
that	O
a	O
compact	O
Clifford	B-Algorithm
–	I-Algorithm
Klein	I-Algorithm
form	I-Algorithm
exists	O
.	O
</s>
<s>
According	O
to	O
Moritz	O
Epple	O
,	O
the	O
Clifford-Klein	B-Algorithm
forms	I-Algorithm
began	O
when	O
W	O
.	O
K	O
.	O
Clifford	O
used	O
quaternions	O
to	O
twist	O
their	O
space	O
.	O
</s>
