3 ms·
2 + 2 = S(S(0)) + S(1) = S(S(S(0)) + 1) = S(S(S(0)) + S(0)) - S(S(S(S(0 + 0)))) = S(S(S(S(0)))) = 4 Definiton of Successor (S) and addition. It's trivial.
by serge2k 10y ago
2 + 2 = S(S(0)) + S(1) = S(S(S(0)) + 1) = S(S(S(0)) + S(0)) - S(S(S(S(0 + 0)))) = S(S(S(S(0)))) = 4
Definiton of Successor (S) and addition. It's trivial.
- fiatjaf 10y agoHow is the definition of Successor so obvious, even if you explain it? How can I understand what it so obviously means?
- serge2k 10y agoIt's an axiom. We are talking specifically about 2+2=4 being trivial because it falls out of the axioms. https://en.wikipedia.org/wiki/Peano_axioms https://en.wikipedia.org/wiki/Peano_axioms