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All elementary functions from a single binary operator

arxiv.org

221–230 of 317 posts

Re: All elementary functions from a single binary operator

#221

Interesting, but is the required combination of EML gates less complex than using other primitives?

Depends on how you define complexity?

Like when the Apollo guidance computer was made, the bottleneck was making integrated chips so they only made one, the NOR gate, and a whackton of routing to build out an entire CPU. Horribly complex routing, very simplified integrated circuit construction

Re: All elementary functions from a single binary operator

#222
post #10

What would physical EML gates be implemented in reality? Posts like these are the reason i check HN every day

Both BJTs and FETs have intrinsic exponential/logarithmic behaviors (at low biases) due to charge density being given by the Fermi-Dirac distribution since electrons are fermions.

Re: All elementary functions from a single binary operator

#223

This is amazing! I love seeing FRACTRAN-shaped things on the homepage :) This reminds me of how 1-bit stacks are encoded in binary: A stack of zeros and ones can be encoded in a single number by keeping with bit-shifting and incrementing. Pushing a 0 onto the stack is equivalent to doubling the number. Pushing a 1 is equivalent to doubling and adding 1. Popping is equivalent to dividing by 2, where the remainder is t…

Did you just explain base-2 numbers on the HN forums as if it were novel?

adding a zero to the left of a binary integer doesn't double it

Re: All elementary functions from a single binary operator

#224

Earlier quoted context omitted.

I think that you may have replied before I saved my entire response, so I am not sure how much of it you had read before replying yourself. I have replied to your last statement: > "you can use the second parameter of a binary function to identify a unary function just as you can use the fourth parameter of a quaternary function to identify a trinary one." As I have explained above, what you propose does not work. It…

> As I have explained above, what you propose does not work. It works in functions with 3 or more parameters, but it does not work in binary functions, because you cannot make binary functions from unary functions (without using some auxiliary binary functions). I have no idea what you're trying to say. If you can use one parameter to identify a desired function, then obviously you can use a function of arity n+1 to…

The subject of the parent article is expressing all the "elementary functions".

This requires expressing binary functions, like addition and multiplication.

You cannot do this by using only the set of unary functions, which can indeed be generated by a function with 2 parameters, one of which selects an unary function.

Re: All elementary functions from a single binary operator

#226

This could have some interesting hardware implications as well - it suggests that a large dedicated silicon instruction set could accelerate any mathematical algorithm provided it can be mapped to this primitive. It also suggests a compiler/translation layer should be possible as well as some novel visualization methods for functions and methods.

I'm not too familiar with the hardware world, but does EML look like the kind of computation that's hardware-friendly? Would love for someone with more expertise to chime in here.

A similar function operating on the real domain for powers and logs of 2 would be extremely hardware friendly. You can build it directly out of the floating point format. First K significand bits index a LUT. Do that for each argument and subtract them.

It gets a bit more difficult for the complex domain because you need rotation.

Re: All elementary functions from a single binary operator

#229

EDIT: please change the article link to the most recent version (as of now still v2), it is currently pointing to the v1 version which misses the figures. I'm still reading this, but if this checks out, this is one of the most significant discoveries in years. Why use splines or polynomials or haphazardly chosen basis functions if you can just fit (gradient descent) your data or wave functions to the proper computati…

The compute, energy, and physical cost of this versus a simple x+y is easily an order of magnitude. It will not replace anything in computing, except maybe fringe experiments.

Re: All elementary functions from a single binary operator

#230
This isn't unique, or even the least compute way to do this. For example, let f(x,y) = 1/(x-y). This too is universal. I think there's a theorem stating for any finite set of binary operators there is a single one replacing it.

write x#y for 1/(x-y).

x#0 = 1/(x-0) = 1/x, so you get reciprocals. Then (x#y)#0 = 1/((1/(x-y)) - 0) = x-y, so subtraction.

it's common problem to show in any (insert various algebraic structure here ) inverse and subtraction gives all 4 elementary ops.

I haven't checked this carefully, but this note seems to give a short proof (modulo knowing some other items...) https://dmg.tuwien.ac.at/goldstern/www/papers/notes/singlebi...

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