>>12135666Not just added and multiplied, but every higher order generalization of these operations.
Multiplication is defined by a*0=0, a*(n+1)=a*n + a
Exponentiation as a^0=1, a^(n+1)=a^n * a
Tetration as a^^0=1, a^^(n+1)=(a^^n)^n
Quatration as a^^^0=1, a^^^(n+1)=(a^^^n)^^a
and so on. You get the picture.
Now in each of these, 2^^2 = 4.
2^^^^2=4, 2^^^^^^^^^^^^^2=4.
Nice.
