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De Bruijn Numerals

6 days ago
  • #de-bruijn-indices
  • #lambda-calculus
  • #numeral-systems
  • Introduction of a novel encoding method called 'de Bruijn numerals' using nested de Bruijn indices.
  • Explanation of the encoding with an example: the decimal number 4 is encoded as λ54.
  • Reference to Wadsworth's (1980) work on numeral systems and the concept of 'adequate' numeral systems.
  • Discussion on the limitations of de Bruijn numerals, particularly the absence of a zero? function.
  • Presentation of arithmetic operations (succ, pred, add) with proofs using β-reduction.
  • Introduction of hybrid implementations combining de Bruijn numerals with Church numerals for operations like multiplication and factorial.
  • Application of de Bruijn numerals in solving practical problems, such as projections in Church n-tuples.
  • Description of functions for manipulating Church n-tuples, including selector, push, pop, and move.
  • Conclusion with an invitation for feedback and further exploration of de Bruijn numerals.