## How to check if guest has placed an order?

I need to check if a guest has placed an order, then show specified text for him if yes.

I know how to search orders by MySQL queries, but have no idea about guests. Any ideas how to identify guests? Should I check by IP or cookies? Maybe you can share code snippet?

## Order of offhand attack and extra attack [duplicate]

• Can you break up your Attack action for a bonus action? 4 answers
• Does it matter which weapon I attack with first when two-weapon fighting? 1 answer

Both two weapon fighting and extra attack give additional attacks in a turn, but in what order do those three attacks take place? Is it up to the player, or must it be a specific order?

My initial assumption is that this would go: (action) attack – extra attack – (bonus action) offhand attack. But since a bonus action can take place at any time on your turn, is the offhand attack allowed to happen before the attack action, as long as you do take the attack action that turn? Or could it happen in the middle of the attack, between your attack and extra attack?

This obviously doesn’t normally matter, but when dealing with multiple enemies, movement, and different weapon enchantments, it could. And since that offhand attack doesn’t get your ability modifier, that could also affect the order one may want to make the attacks.

For instance, your off-hand flame-tongue might easily take down the fire-weak enemy in front of you, while your primary hand weapon could be used to attack an enemy 15 feet away – but you need to take care of this enemy before moving to avoid the opportunity attack.

## Abusing ElGamal in order to attack a known encrypted text

I saw a very interesting question regarding Elgamal cryptosystem that I don’t know its answer. It is really interesting and I would be very happy if you could elaborate on it and explain the tricky part.

It goes like this: given Elgamal Cryptosystem:

1) Show how it is possible to create a valid new encryption from two different encryptions that we don’t know their decryption

2)How can an adversary take advantage of this property in order to attack a known encrypted text?

I don’t understand it, and it seems really cryptic and interesting. Tried digging on it but couldn’t find the connection or insights.

Seems really fascinating, would appreciate if you could explain it so I can understand this riddle.

## What could be the bound of the number of elements of a models of a given first order sentence?

Sorry for the weird title.

The Problem:

Consider the first-order logic sentence

φ≡∃s∃t∃u∀v∀w∀x∀yψ(s,t,u,v,w,x,y) where ψ(s,t,u,v,w,x,y,) is a quantifier-free first-order logic formula using only predicate symbols, and possibly equality, but no function symbols. Suppose φ has a model with a universe containing 7 elements.

Which one of the following statements is necessarily true?

1. There exists at least one model of φ with universe of size less than or equal to 3
2. There exists no model of φ with universe of size less than or equal to 3
3. There exists no model of φ with universe size of greater than 7
4. Every model of φ has a universe of size equal to 7

My attempt:
There exist at least one s,t, and u in some domain. It is also given that there exist a model with 7 elements. i.e there is at least one instance of v,w,x and y as well, together making 7 elements with s,t,u. So any other model of φ must have at least these 7 elements as well. Any model cannot have more than seven elements because there are only seven given. i.e every model of φ will have exactly seven elements. So Option 4 seems to be the right one.

I wish to develop intuition to solve these problems. Also I want to know your thought process and how you solve this problem. Thanks.

## A Question About the Order of Learning from the Book “Lectures on the Curry-Howard Isomorphism” (1998)

I’m learning from this book: https://disi.unitn.it/~bernardi/RSISE11/Papers/curry-howard.pdf (Lectures on Curry-Howard Isomorphism – 1998 version) for some project. And due to time constraints, I probably won’t be able to cover all of the material in the book, in my study. Luckily, although it would be useful,I don’t think I will need to know everything in this book, but rather selected topics. At the moment, I learned the first chapter and something like a third of the second chapter, and from what I learned so far in the second chapter it seems like you don’t actually need to know the first chapter in order to learn this chapter, it seems like the two chapters cover separate topics. So, perhaps that’s true for other chapters as well. Of course, some of them will require knowledge of previous chapters, especially, I can imagine the 4th chapter on the Curry-Howard isomorphism, but even the chapters that require knowledge of previous chapters, might not require all the previous chapters.

So, it could be very helpful if someone with experience with the topics covered in this book, could list to each chapter all the prerequisites for learning it. Especially, for chapters 4 and 11 (Heyting Arithmetic), that cover material that I totally need.

## Is there any hook or filter that user data, specifically email address, is passed through on new order creation?

I want to create a function/module that corrects common email typos on new orders.

For example to auto correct gmail.con, hotmail.con to .com, and many many more common typos.

Is there any hook or filter that user data, specifically email address, is passed through on new order creation, so that we can modify it before it’s inserted into the database?

## Do you need to be aware that the target wants to teleport, in order to Shadow Pin it?

There’s ways to recognize which spell or maneuver is being used: is this needed before using the Shadow Pin counter?

Or do you just instantly stop it while it’s happening?

## Inorder tree tranversal on binary search tree doesn’t give the elements in order?

I have been told that inorder tree tranversal of binary search trees returns the tree elements in order. I came up with this binary search tree:

      20     /  10     \      26 

However the inorder tree tranversal of this seems to be 10, 26, 20?! What is wrong here?

## Can full first order knowledge base be written as the single sequent in the sequent calculus?

The knowledge base of the first order logic essentially is single formula: conjunction of individual formulas (I guess, I am right). The sequent for the sequent calculus is the formula in the special form – it is implication with the conjunction on the left hand side and the disjunction on the right hand side. Turnstile symbol and commas can be used to write down this special knid of formula. I have heard, that every FOL formula can be rewritten as the sequent, am I right. Then one can conclude that every knowlege base can be written as the single sequent. And every reasoning over this knowledge base can be expressed as the application of the sequent rules (in top-down or bottom-up direction). Am I right?

Am I right about this format? And why the sequent calculus are not used wider in the practical applications, implementations of the knowledge bases?

## Encoding order relations in CNF

I want convert timetable scheduling problems to SAT problems. Suppose there are $$t$$ time slots and $$c$$ classes. I will define $$t\times c$$ variables $$x_{ij}$$, which is true iff class $$j$$ takes place in time slot $$i$$. My problem is: suppose there is a constraint that class $$a$$ takes place after class $$b$$. How to encode that efficiently in CNF?