# How is this read correctly (problem with brackets)? 2^2048 - 2^1984 - 1 + 2^64 * { [2^1918 pi] + 124476 }

How do you read this correctly, where are the brackets if you set them?

2^2048 - 2^1984 - 1 + 2^64 * { [2^1918 pi] + 124476 }

Taken from: https://www.ietf.org/rfc/rfc3526.txt I have great problems solving this because I don't know how it is read correctly... There are some important brackets missing for me and I could write several different ways how it could be read and I don't know which one is correct. Maybe there is a rule for that which I don't know?

I would read it like that but because the numbers are that huge and there are several possibilities, it's very hard to know which result is correct:

$$2^{2048} - 2^{1984}-1+2^{64} \cdot (2^{1918 \pi} + 124476)$$

• $2^{2048} - 2^{1984}-1+2^{64} \cdot (2^{1918 \pi} + 124476)$ seems okay. But maybe $[]$ are floor function? – Nyssa Jun 10 at 23:17

It seems that the correct writing of your number is $$c=2^{2048}-2^{1984}-1+2^{64}\cdot\bigl(\,\lfloor2^{1918}\,\pi\rfloor +124476\bigr)\ .$$ This $$c$$ has $$617$$ decimal digits. Its conversion to hexadecimal is
$$2^{2048} - 2^{1984}-1+2^{64} \cdot (2^{1918\times 3} + 124476)$$, when converted to decimal contains 1752 digits.
However, replacing $$2^{1918\times 3}$$ with $$2^{1918}\times 3$$ also contains 617 digits, so this interpretation may be the correct one.
Note that in my calculations I have replaced $$\pi$$ with $$3$$.