Example of ID: Natural Numbers
w
lBasis: 0 is in w.
lInduction: If n
is in w, so is the successor of n (variously denoted nе, S(n), or n+1).
lExtremal: The
only elements in w are those derivable by applications
of the above rules.
lExamples: 0, 0е, 0ее, 0еее, 0ееее, Щ are all elements of w.