## Why is a Context Free Grammar that is simultaneously in Chomsky Normal Form and Greibach Normal Form regular?

In my course materials, there is one sentence about how if CFG is in Chomsky Normal Form, it is not regular, and if it is in Greibach Normal form, it also is not. But when a grammar is simultaneously both GNF and CNF, it somehow implies that the grammar is regular – why is it so?

I struggle to understand what would the productions of the grammar that is both in CNF and GNF look like. As in GNF, the production rule is in form: $$A \rightarrow aA_1A_2…A_n$$ such that the nonterminal sequence can be empty, I think that the only way a grammar can be in both normal forms, is when the production rules are in form: $$A \rightarrow a$$.

Even if this is the case, why does it imply that the grammar is regular? What is the relationship between regular and context-free grammar?

## Do Blink, Blur, normal concealment & Displacement stack?

Just what the title says, Do Blink, Blur, normal concealment & Displacement stack? Do any of them stack? Do all of them stack? Which ones, if any?

## Can I use the same weapon for a normal attack and Two-Weapon Fighting in the same turn?

Two-weapon fighting rules, per the Player’s Handbook (page 195):

When you take the Attack action and attack with a light melee weapon that you’re holding in one hand, you can use a bonus action to attack with a different light melee weapon that you’re holding in the other hand. You don’t add your ability modifier to the damage of the bonus attack, unless that modifier is negative.

Per my earlier question, I am allowed to use different weapons for an Attack action if I have the Extra Attack class feature. Let’s assume I did just that, attacking once each with a hand-axe and once with a shortsword. Am I allowed to afterwards perform a Two Weapon Fighting bonus attack with one of these weapons?

## Third Normal Form and Boyce Code normal form

I know that this is not a question answer site but for sake of explaining my doubt I have to post the entire question..

Consider the following statements.

If relation R is in 3NF and every key is simple, then R is in BCNF If relation R is in 3NF and R has only one key, then R is in BCNF  Both 1 and 2 are true 1 is true but 2 is false 1 is false and 2 is true Both 1 and 2 are false 

Ans given is $$a$$, but how can it be so?

I agree with the first statement but for the second one consider that we have a relation $$R={\{A,B,C,D\}}$$ where $$AB$$ is the key, and say $$C->B$$ then it satisfies $$3nf$$ right? But it is $$NOT$$ in $$BCNF$$ right? as here we have $$non-prime$$ $$deriving$$ $$a$$ $$prime$$ $$attribute$$

## Does normal use of ECC violates ECC Patents?

I’ve got a few questions regarding Elliptic-curve Cryptography (ECC) Patents.

My Company runs its own Certificate Authority. Root CA and Intermediate CA Key are generated using ECC 384-Bit (secp384r1). End Entity keys are generated using ECC 256-bit (prime256v1).

We use our CA for all sorts of things from Websites to VPNs. ECC is used extensively everywhere in our Company.

But yesterday, I came across ECC Patents and I’m worried about it. Certicom already used Companies such as Sony, Netflix, AT&T, etc for using ECC. We don’t really want to take any risk for legal trouble just for using ECC.

Does normal use for ECC violate Patent? Or using RSA would be a good choice to stay on the safe side? (We’re in the Beta stage not in Production so switching from ECC to RSA won’t be painful)

P.S- This question might be related to some previous asked ECC Patents but I believe creating a new thread would be great because I was unable to get my answer.

## How do I gain extra feats outside of normal levelling?

I’m new to D&D and new to version 3.5 particularly.

I’m creating a character using the PHB and need to know if there are any means for getting extra feats – perhaps some items or possibly quests?

This knowledge is very crucial for building characters, as two sets (for 7 feats and for 9 feats) differ dramatically.

The DM says that for a novice, using PHB1, PHB2, Complete Arcana, Complete Divine, Complete Warrior, Complete Adventurer and DMG1 (prestige class section only) are sufficient, but he may for his own needs draw events, rewards and so on from additional sources.

I’m planing to breed Cleric lvl1, Wizard Lvl4, Dweomerkeeper lvl 10 (we agreed with DM to override experience cheat of this class) , Archmage lvl 5.

Three of my feats go towards archmage prereqs, eschew materials, and some metamagic. For others I may get more metamagic or get SLA from Archmage and use maximize SLA on it, or get extremely useful precise shot for not hitting my own companions that are all melee.

## example of an aegis normal day

So finally: In the morning the 3 lev Aegis wake up and choose ‘speed’ for a.skin (free), ‘brawn’ for a.armor (free) and ‘hardy’ for a.juggernaut (free) and he active the a.skin and starts the Adventure, then he had to lift a big rock so dismiss a.skin and wear the a.armor to gain ST+2, do it the Aegis dismiss a.armor and wear a.skin again to obtain ‘speed’. Then he face a giant spider so he decide to switch to a.juggernaut to gain ‘hardy’ and so he kill it. He undress the a.juggernaut and wear again a.skin with ‘speed’ to chase some goblins and then he reconfigure (with His new ‘reconfigure’ ability 1perday) His a.skin with nimble to gain DEX+2 to finish them with bow and arrows. All this path without pay customization points. At least the Aegis decide to dismiss a.skin and wear again a.juggernaut but he cant reconfigure it in stalwart customization cause he dont have more way to reconfigure it so the suit continue to affect him with ‘hardy’. Thats correct?

## Why Stored Procedure taking extra time then , normal query execution(MYSQL)?

I have one stored procedure which returning single but taking 16+ seconds when I call that but only .5 second, if I run that by normal query.

Procedure

    DELIMITER    DROP PROCEDURE IF EXISTS local_db.getAllMatchedStockByCompany    CREATE     PROCEDURE local_db.getAllMatchedStockByCompany(     IN Company_ID BIGINT(20)     )     BEGIN         SELECT t1.*     FROM ((SELECT t2.SRTitle,t2.UrlPart,t2.ScheduledTime,t2.Photo,TRIM(REPLACE(REPLACE(REPLACE(REPLACE(SUBSTRING_INDEX(REPLACE(fnStripTags(t2.SRDescription),'&nbsp;',''),' ',             30), '\r\n\t\r\n\r\n\t', ''),'\r\n\t\r\n\t',''),'\r\n\t',''),'&rsquo;',''))AS Description, 'stock-research' AS from_tbl,t2.IsActive            ,t2.CompanyID FROM t2           ) UNION           (SELECT t3.ReportTitle,t3.UrlPart,t3.CreatedDate,t3.ReportImage,TRIM(REPLACE(REPLACE(SUBSTRING_INDEX(REPLACE(fnStripTags(t3.Description),'&nbsp;',''),' ',                 30),'\r\n\t\r\n\t',''),'&#39;','')),IF(t3.SpecialReport = 1,'special-report','report'),t3.IsActive         ,t3.CompanyID FROM t3           )          ) t1          WHERE CompanyID = Company_ID AND IsActive = 1          ORDER BY ScheduledTime DESC;     END    DELIMITER ; 

the total execution time of this is 16 seconds with 1 row. But If I use below query

SELECT t1.*     FROM ((SELECT t2.SRTitle,t2.UrlPart,t2.ScheduledTime,t2.Photo,TRIM(REPLACE(REPLACE(REPLACE(REPLACE(SUBSTRING_INDEX(REPLACE(fnStripTags(t2.SRDescription),'&nbsp;',''),' ',             30), '\r\n\t\r\n\r\n\t', ''),'\r\n\t\r\n\t',''),'\r\n\t',''),'&rsquo;',''))AS Description, 'stock-research' AS from_tbl,t2.IsActive            ,t2.CompanyID FROM t2           ) UNION           (SELECT t3.ReportTitle,t3.UrlPart,t3.CreatedDate,t3.ReportImage,TRIM(REPLACE(REPLACE(SUBSTRING_INDEX(REPLACE(fnStripTags(t3.Description),'&nbsp;',''),' ',                 30),'\r\n\t\r\n\t',''),'&#39;','')),IF(t3.SpecialReport = 1,'special-report','report'),t3.IsActive         ,t3.CompanyID FROM t3           )          ) t1          WHERE CompanyID = 931 AND IsActive = 1          ORDER BY ScheduledTime DESC; 

It took only .5 to 1 seconds with one row.

Can anyone of you let me why this happening or How I can improve my SP execution time?

Thanks

## Can I regain some of my normal hit points while I have a buffer of temporary hit points?

If my character has 50 hp, loses 20 hp, and I then cast a 25 thp armor of agathys, what happens if I’m using something like Grim Harvest, Vampiric Touch or Enervation, each of which restore normal hp?

Obviously my pool of normal hp is depleted, do these spells replenish that even if I have a thp buffer on top?