1.NounA method of proof which, in terms of a predicate P, could be stated as: if
P
(
0
)
{\displaystyle P(0)}
is true and if for any natural number
n
≥
0
{\displaystyle n\geq 0}
,
P
(
n
)
{\displaystyle P(n)}
implies
P
(
n
+
1
)
{\displaystyle P(n+1)}
, then
P
(
n
)
{\displaystyle P(n)}
is true for any natural number n.