398
1 + 1
(mander.xyz)
A place for majestic STEMLORD peacocking, as well as memes about the realities of working in a lab.
Rules
This is a science community. We use the Dawkins definition of meme.
Now define "+"
+
is a map fromN×N
toN
wherea + 0 = a
anda + S(b) = S(a + b)
(S
is the successor function that gives the next number).Then
1 + 1 = 1 + S(0) = S(1 + 0) = S(1) = 2
.seems a little sus to use + to define +
No, it's correct. You define the operation by it's properties. It's not saying that "a plus 0 = a" but "the result of applying the binary operation '+' to any number with 0 should give the original number."
You have to have previously defined 1=S(0), 2=S(1), 3=S(2), and so on.