<s>
An	O
ordinal	B-Application
tree	I-Application
,	O
by	O
analogy	O
with	O
an	O
ordinal	B-Language
number	I-Language
,	O
is	O
a	O
rooted	O
tree	O
of	O
arbitrary	O
degree	O
in	O
which	O
the	O
children	O
of	O
each	O
node	O
are	O
ordered	O
,	O
so	O
that	O
one	O
refers	O
to	O
the	O
ith	O
child	O
in	O
the	O
sequence	O
of	O
children	O
of	O
a	O
node	O
.	O
</s>
