132
What is 2?
(lemmy.blahaj.zone)
Context:
In ZFC set theory (which most of modern maths is built upon). The natural numbers are defined as recursions of empty sets.
Ie. 0 = ∅ (the empty set)
1 = {∅} = {0}
2 = {∅, {∅}} etc…
might as well take a safety factor of 2, so I can use τ, which requires less tie to write than π (I am a engineer)