Is there a word for the fact that all data representations are equal?

For programming languages, we have the concept of Turing completeness which expresses the fact that all computers and all languages are equal in their ability to represent any algorithm so long as we ignore the capacity of the storage medium. Is there a similar word for data encodings/representations?

For example, any number can be represented in unary, binary, ternary form. So long as all the data structures have the same “data capacity” between any given 2 structures A and B there exist functions:

to :: A → B from :: B → A 

Where from ∘ to == id.

This is obviously true for any (context insensitive) data structure that exists in a computer because they are literally all just strings of bits. But what is the word for this?

Is there any action cost for a Kinetecist when using Metakinesis?

So, kinetecists can use metakinesis to affect their blasts as if by using an associated metamagic feat. Metamagic feats sometimes modify the action required to use the associated spell (i.e. standard action –> full round).

Does empower metakinesis, for example, actually modify the time it takes to use a kinetic blast? Or does it remain a standard action.

Is there Vehicle Speed Errata for the DMG?

Recently, I have have been preparing the times for journeys over land and by sea for an upcoming session. When I told my players about my calculations, one of them said that my info in the DMG under the sailing ships speed has been Errata’d in the WotC Sage Advice blog. After hours of combing the website and google, I can find no errata specifically about vehicle speeds. Is there such errata?

My google searches in regards to sailing speeds gave me the target range of 5-8 knots on average (5 knots comes in close to 6mph vs DMG saying 2mph) So if there is Errata for this I’d like to know about it so I dont unfairly slow the estimated sea voyage travel time. I know I could house rule this, but I’d prefer seeing the supposed errata this player saw a reference to on reddit. Given that it’s reddit, I already doubt its legitimacy, but I’d be a terrible DM if I didn’t do my due diligence and ask around for official Rulings on this stuff.

Is there a function that is hard to find elements not in its image

I posted that in theoretical CS, but perhaps it is also relevant here.
Informally, a function $ f:\{0,1\}^* \rightarrow\{0,1\}^*$ is one way function (OWF) if it is easy to compute, but difficult to invert.
Assuming the existence of OWF, is there a function $ f : \{0,1 \}^* \rightarrow \{0,1\}^*$ such that it is hard to find $ y$ which is not in the image of $ f$ , i.e. $ y : \forall x, f(x) \neq y$ , given that such $ y$ exists? Does it necessary to assume the existence of OWF for such $ f$ ?
Formally,

  1. $ f$ can be computed in polynomial time.
  2. For every algorithm $ A$ in $ BPP$ , for all positive integers $ c$ and large enough $ n$ , $ $ \Pr(\exists u:f(u)=A(x)) \leq n^{-c} $ $ Where $ x$ is chosen from the uniform distribution over $ \{0,1\}^n$ .

Is there a term for the psychological issue of “code loss” for programmers?

(Note: I wanted to post this to the “Psychology” category, but it had no matching tags at all.)

I am a programmer. I have just deleted a huge amount of code which I painstakingly researched, thought about, coded, then improved and fixed as bugs popped up for a long time.

All of that code, which took me a ridiculous amount of time, effort and general “mind work”, has now been replaced by a very small number of lines which basically leverage PHP’s built-in “ICU” features to properly output numbers, money sums and date/time in the correct manner for every combination of language, locale, currency and timezone imaginable.

Previously, I did not know that this already existed, so I basically replicated a lot of it myself, and I now realize how far from perfect it was. But still, I did it, and that code had in my mind “hardened” or “settled” as “gold code” which I never thought I would touch again…

Basically, I mourn my now useless, superseded, obsolete code chunks. I’m annoyed by myself for doing all that unnecessary work and it took a lot of mental wrestling to finally convince myself to go through with it.

Is this common among programmers, and does it have an established term? Such as “code loss” or “code mourning”?

Basically, even though I have really improved my application/library/framework to an extreme degree, it still feels like I’ve “lost all that work” because the numbers of lines are slashed so much in one go. It’s not a nice feeling.

Are there any examples in published D&D material of how to destroy a lich’s phylactery?

According to the D&D 5e Monster Manual, regarding destroying a phylactery, it says:

Destroying a lich’s phylactery is no easy task and often requires a special ritual, item, or weapon. Every phylactery is unique, and discovering the key to its destruction is a quest in and of itself.

— p. 203, Death and Restoration

However, no further information is given on how this is typically done, or what is involved specifically.

I get that this is meant as a plot hook for the DM, and that the DM is meant to fill in the blanks as befits their story/campaign, and that the intention here is that different lich’s phylacteries must be destroyed in different ways, rather than a one-size-fits-all method for destroying any phylactery.

However, it would be easier for me to come up with something if I had some examples to work with from existing adventures or additional lore on liches not included in the D&D 5e Monster Manual. Is there anything published in any edition of D&D that describes how to destroy a (specific) lich’s phylactery?

Is there ever a case where a creature gets a saving throw against the “Sleep” spell?

The sleep spell (PHB 276) states:

This spell sends creatures into a magical slumber. Roll 5d8; the total is how many hit points of creatures this spell can affect.

This and other similar spells like color spray affect a pool of hit points directly, not dealing damage and encountering potential resistances nor requiring a saving throw that may be given advantage via mechanics.

There are creatures that explicitly give advantage on saving throws against being put to sleep magically, though, such as the Bugbear Chief (MM 33), which has the trait Heart of Hruggek:

The bugbear has advantage on saving throws against being charmed, frightened, paralyzed, poisoned, stunned, or put to sleep.

(Emphasis mine)

or the Balor (MM 55), which has the trait Magic Resistance:

The balor has advantage on saving throws against spells and other magical effects.

(Emphasis mine)

Sleep in this case comes from a magical source, so I believe it falls under the category of a magical effect.

Given these specific wordings, does the general behavior of the sleep spell change to fit the circumstance, giving the targeted creature a saving throw against the caster’s DC? If so, what type of saving throw? Or does the spell simply ignore these traits and proceed to affect the hit point pool directly?