Difference between revisions of "Natural Numbers:Postulates"

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# If two numbers <math> n_1 </math> and <math> n_2 </math> have the same successor, then <math> n_1 = n_2 </math>.
 
# If two numbers <math> n_1 </math> and <math> n_2 </math> have the same successor, then <math> n_1 = n_2 </math>.
 
# If a set <math> S </math> contains 1, and also contains the successor of every element <math> n </math> in <math> S </math>, then every natural number is in <math> S </math>.
 
# If a set <math> S </math> contains 1, and also contains the successor of every element <math> n </math> in <math> S </math>, then every natural number is in <math> S </math>.
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These axioms are used to build the set of natural numbers <math> \N = \{1, 2, 3,..., n, n + 1,...\} </math>.

Revision as of 11:28, 1 October 2021

Peano's Axioms for the Natural Numbers

  1. 1 is a natural number.
  2. For every natural number , the successor to , (), is also a natural number.
  3. 1 is not a successor to any natural number.
  4. If two numbers and have the same successor, then Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle n_1 = n_2 } .
  5. If a set Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle S } contains 1, and also contains the successor of every element Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle n } in Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle S } , then every natural number is in Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle S } .

These axioms are used to build the set of natural numbers Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \N = \{1, 2, 3,..., n, n + 1,...\} } .