In classical computing, what is meant by a bit string function?

Question

What is exactly meant by this function? I haven't found any clarification how exactly this function works:

$$f: \{0,1\}^n \rightarrow \{0,1\}^m$$

So it takes a n-bit string and turns it into an m-bit string but what is meant by a bit string and what are some examples of this function? Is a bit string 010101010101? This then gets put into the function and this turns into another bit string?

It is a function that maps stings of $n$ bits into strings of $m$ bits. — Mauro ALLEGRANZA, Mar 11 '21 at 10:55
An yes; a bit string is a finite sequence of bits: either $0$ or $1$. — Mauro ALLEGRANZA, Mar 11 '21 at 10:55
So what first happens is the word "Hello" gets translated into a bit string, then this bit string goes through a function and spews out a different bit string. Is that correct? — mikanim, Mar 11 '21 at 10:56
Yes, probably the computer still uses ASCII code where each character is coded as an hexadecimal number that in turn is a bit string. — Mauro ALLEGRANZA, Mar 11 '21 at 11:00

Steven01123581321 · Answer 1 · 2021-03-11T12:39:20.020

Bit-strings just represent subsets of sets where a $1$ means the corresponding element of the set is included in the subset, and $0$ means it is excluded from your subset.

So if you have the following set: $\{2,3,5,8,13\}$ then the first bit in our bit-string corresponds to 2, the second to 3, the third to 5, the fourth to 8 and the fifth to $13$.

e.g. if you take a bit-string defined as $10110$, this represents a subset of our previous defined set as : $\{2,5,8\}$

In classical computing, what is meant by a bit string function?

1 Answers1