Derive all four propositional logic operators from nand

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Discussion Overview

The discussion centers on the derivation of all four propositional logic operators (negation, disjunction, conjunction, and implication) from the NAND operator. Participants explore the implications of this derivation in both theoretical and practical contexts, including its relevance to electronic components.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant explains that all four propositional logic operators can be derived from the NAND operator, providing specific definitions and truth tables for each operator.
  • Another participant expresses curiosity about the practical implications of using NAND gates in electronics, questioning whether their prevalence is due to simplicity or cost-effectiveness.
  • A later reply reflects on the historical perspective of logic, noting a shift in focus from implication and negation as basic components to the importance of disjunction and conjunction in programming.
  • One participant introduces the NOR operator as another foundational logic gate, suggesting it may also have similar properties.

Areas of Agreement / Disagreement

Participants generally agree on the interesting nature of deriving logic operators from NAND, but there are multiple competing views regarding the reasons for the prevalence of NAND gates in electronics and the foundational components of logic.

Contextual Notes

Participants express uncertainty about the cost implications of using NAND gates in electronics and the historical context of logic development, indicating that these factors may influence the discussion but remain unresolved.

Who May Find This Useful

This discussion may be of interest to those studying logic, computer science, electronics, or the philosophy of logic.

Uvohtufo
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So I recently learned that you can derive all four of the propositional logic operators (~, V, &, →) from Nand alone.

As I have understood it, so long as you have negation, and one of the other operators, you can derive the rest. Like P → Q can be defined as ~P V Q.

However, I learned that if you start with the Nand (Not and) operator, you can derive all four. I'll use ' N ' to designate Nand.

The truth table for Nand being
P Q | P N Q
T T | F
F T | T
T F | T
F F | T

~P := P N P
P & Q := (P N Q) N (P N Q)
P V Q := (P N P) N (Q N Q)
P -> Q := (P N Q) N (Q N Q)

Isn't that cool?
 
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Yes, it's cool.

I wonder if that explains why NAND gates are common electronic components. But perhaps NAND gates are common only because the circuit is simple to construct.
 
Stephen Tashi said:
Yes, it's cool.

I wonder if that explains why NAND gates are common electronic components. But perhaps NAND gates are common only because the circuit is simple to construct.

Yeah I am not sure.

I think its interesting how when symbolic logic was being invented, implication and negation were viewed as the basic components of logic. Today it seems like programmers view and or or and negation as basic parts.

Unlike philosophers or programmers, electronics people have a cost constraint. Nand is simpler, but is it cheapest?
 
You have also NOR.
 

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