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 Derivation of the Safety Stock Formula on Wikipedia
 Introduction to C*algebra theory by Pedersen
 minima of a multivariate function
 Does every power of two arise as the difference of two primes?
 Does the Kaprekar process survive probability?
 Basis for $\mathfrak{sl}(2,R)$ in terms of coordinate basis (or vice versa)
 interchanging limits and derivatives: Terence Tao real analysis example
 How to get the idea behind the relationship between angles and sides?
 Making plane parallel to xy axis
 Consequences of $X X^T = Y Y^T$
 Finding the number of zeros of a polynomial in the closed disk
 Differentiability implies continuity in higher dimension
 Is the complement of a directed and not strongly connected graph connected?
 Existence of $x\in \mathcal{X}$ such that $\x\=1$ and $\x+\mathcal{M}\=1$ for a closed subspace $\mathcal{M}$
 Lipschitz Continuity in one variable of a several variable function
 Types and automorphisms in model theory
 What do we call this operation? Unitary matrix?
 Convex functions in Inequality
 For what values of $a$ and $b$ does $\lim_{x\rightarrow \infty}(\sqrt{x^2+x+1}axb)=1$?
How to get transactions on only one Ethereum address?
Imagine this scenario:
ACME company is selling a service for 1 AcmeToken to their users.
When a user wants to buy the service, ACME company generates a new Eth address for the user, so there is an association between EthereumAddresses and Users in the company database.
Unfortunately, this common scenario has one problem:
When the company wants to withdraw the tokens from all the addresses they generated, the company may spend a lot of ETH to cover GAS price costs.
So, I trasformed the scenario in this way:
The company receives all the tokens on one single Ethereum address and asks the transaction hash to the user, but.. in this way the user could take old transactions hashes to the same address, so I'm not considering proceeding this way so safe and secure.
How would you identify a single transaction in a safe way without creating a lot of addresses?
Have people sign up with their Metamask/Cipher/etc. the way sites like cryptokitties do, by giving them a ran

Have people sign up with their Metamask/Cipher/etc. the way sites like cryptokitties do, by giving them a random message to sign to verify they have the private key to that address. Then have them all send to one address, and every time there is a new transaction, just check what user has that address.
20180721 19:35:25