$ mathbb N $中$ 0的歷史。


6

在$ mathbb N $中是否$ 0有不同的約定。

我知道$ \ mathbb N = \ {0,1,2,3,\ cdots \} $被稱為$ \ mathbb N $的Bourbakian定義。但是這個約定真的來自Bourbaki嗎?

在更早的Peano公理中,0也被視為自然數。

那麼每個約定($ mathbb N $中的$ 0和$ mathbb N $中的$ 0 \ not \)在哪裡形成?

10

For modern times:

§71. Definition. A system $N$ [Ein system $N$] is said to be simply infinite when there exists a similar transformation $\phi$ of $N$ in itself such that $N$ appears as chain of an element not contained in $\phi(N)$. We call this element, which we shall denote in what follows by the symbol $1$, the base-element of N and say the simply infinite system $N$ is set in order by this transformation $\phi$.

[...]

§73. Definition. If in the consideration of a simply infinite system $N$ set in order by a transformation $\phi$ [...] these elements [are] called natural numbers or ordinal numbers or simply numbers, and the base-element $1$ is called the base-number of the number-series $N$.

Axiomata

  1. $1 \in N$

§74. Null [$0$] ist die Anzahl, welche dem Begriffe "sich selbst ungleich" zukommt.

§120. Peano’s three indefinables are $0$, finite integer and successor of. [...] Peano’s primitive propositions are then the following.

(1) $0$ is a number.

$\gamma.$ There is at least one number that is not the successor of any number. [...]

$f.$ The number $0$ that is not the successor of any number [...] is given the name zero.


For Bourbaki, see:

1. Le cardinal d'un ensemble

On note $0$ le cardinal $\text {Card} (\emptyset)$.


1

Originally zero was not considered a natural number. In fact it is one of the most unnatural numbers. Since the word "progression naturelle" was introduced by Chuquet, in 1484 and "natural number" by Emmerson in 1763 always the sequence starting with 1 has been addressed. "Natural number, defined as the numbers 1, 2, 3, 4, 5, etc., appears in the 1771 Encyclopaedia Britannica in the Logarithm article." http://jeff560.tripod.com/n.html Cantor for instance (although rarely using this wording but prefering "integers" (ganze Zahlen) mentiones the "natural sequence of numbers" (natürliche Zahlenreihe): $1, 2, 3, ...,\nu , ...$" in Über unendliche lineare Punktmannigfaltigkeiten Math. Annalen 15, (1879). Also Peano started with 1 in his first papers. Later he switched to 0 like many others. (See the answer by Mauro Allegranza)

Where did these conventions come from? What was the reason for this change? Cantor explained it in a letter to Dedekind of Juli 28,1899: The sequence of ordinal numbers $0, 1, 2, 3, ... ,\omega_0, \omega_0 + 1, ..., \gamma,.. $ has the property that every number is the ordinal type of the preceding numbers. Without including zero this property would not be satisfied for the finite part.

I think that this is the reason.