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and the later use of Peano's notation by Bertrand Russell.

For example, if P(n) is the predicate "2·n > 2 + n" and N is the set of natural numbers, then
: is the (false) statement
:"for all natural numbers n, one has 2·n > 2 + n".

Similarly, if Q(n) is the predicate "n is composite", then
: is the (true) statement
:"for all natural numbers n, if n is composite, then 2·''n'' > 2 + n".

Several variations

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