Bourbaki

Corollary

Tag 03R2, permanent. Cite it as [Bourbaki, Tag 03R2].

Theory of Sets, chapter III, § 3. Equipotent sets. Cardinals

Let a\mathfrak{a}, b\mathfrak{b}, c\mathfrak{c} be cardinals. Then

(1)

a+b=b+a,ab=ba;\mathfrak{a} + \mathfrak{b} = \mathfrak{b} + \mathfrak{a}, \qquad \mathfrak{a}\mathfrak{b} = \mathfrak{b}\mathfrak{a};
(2)
a+(b+c)=(a+b)+c,a(bc)=(ab)c;\mathfrak{a} + (\mathfrak{b} + \mathfrak{c}) = (\mathfrak{a} + \mathfrak{b}) + \mathfrak{c}, \qquad \mathfrak{a}(\mathfrak{b}\mathfrak{c}) = (\mathfrak{a}\mathfrak{b})\mathfrak{c};
(3)
a(b+c)=ab+ac.\mathfrak{a}(\mathfrak{b} + \mathfrak{c}) = \mathfrak{a}\mathfrak{b} + \mathfrak{a}\mathfrak{c}.

Bourbaki sets the proof directly after the statement, and the corpus does not separate them, so what is above is the statement and its proof together.

Cited by

  • alg-i-s1-n3-exa-1 not in this corpus
  • alg-i-s1-n5-exa-1 not in this corpus
  • alg-i-s2-lem-2 not in this corpus
  • Proposition 1, § 5

Cites

Nothing.

Transcribed from the printed edition, 2004, Springer. Not translated.