by the empty set .
# An -tuple, with , can be defined as an ordered pair of its first entry and an -tuple (which contains the remaining entries when :
#: This definition can be applied recursively to the -tuple:
:

Thus, for example:
:

A variant of this definition starts "peeling off" elements from the other end:
# The 0-tuple is the empty set .
# For :
#: This definition can be applied recursively:
:

Thus, for example:
:

Tuples as nested sets

Using Kuratowski's representation for an ordered pair,

1.Previous
3.Next