More errata

[amackay]

I recently read the Metamath book (great book and system!) and noticed some minor errors. This PR suggests fixes.

Most of the changes are trivial grammar or spelling fixes, but there is also:

• "Tarsky-Grothendieck" -> "Tarski-Grothendieck" (the correct spelling AFAICT)
• "there is at least one" -> "there is exactly one", for the description of df-eu
• Removed some duplicate bracketed text, as already mentioned in the errata
• Added an errata item about seemingly duplicate command output

Note that the "./generate-pdf" command produces warnings for me (although it did so even before I made any changes), so I can't be certain I haven't broken any formatting.

Let me know if you'd like any changes - eg. perhaps I am supposed to add to Errata.md but leave metamath.tex untouched? This PR fixes several issues mentioned in the errata, so should I remove those items from the errata and update the date at the top?

[nmegill]

@amackay Thank your for these errata!

@david-a-wheeler Could you look this over and do the merge? Thanks. Also, are we keeping the .tex/.pdf updated, or are we just keeping an errata list so that the pdf matches the published book?

[david-a-wheeler]

@nmegill - up this point I think we've only been editing the errata. But eventually we'll need to modify the text itself if we're going to ever release an update.

I propose that we edit the errata to note all changes from the 2019-06-02 book (errata.md), and that we edit the .tex file (metamath.tex).

I think the main Metamath site should just refer to the frozen 2019-06-02 version for now, otherwise there will be confusion when people refer to the physical book vs. the files.

Thoughts?

[david-a-wheeler]

No reason to be coy. It is shown twice :-).

[amackay]

Hehe okay. Updated to be less coy.

[nmegill]

@nmegill - up this point I think we've only been editing the errata. But eventually we'll need to modify the text itself if we're going to ever release an update.

I propose that we edit the errata to note all changes from the 2019-06-02 book (errata.md), and that we edit the .tex file (metamath.tex).

I agree.

I think the main Metamath site should just refer to the frozen 2019-06-02 version for now, otherwise there will be confusion when people refer to the physical book vs. the files.

I agree.

[amackay]

@nmegill - up this point I think we've only been editing the errata. But eventually we'll need to modify the text itself if we're going to ever release an update.
I propose that we edit the errata to note all changes from the 2019-06-02 book (errata.md), and that we edit the .tex file (metamath.tex).

I agree.

Makes sense. In that case, maybe errata.md could also keep track of which issues have already been fixed, by marking them with an asterisk. Something like this:

The following are errata for the Metamath 2019 ("Second Edition") book
dated 2019-06-02. Issues fixed in the latest github version are marked with (*).

• *Preface (Note Added March 7, 2019) - Matamath --> Metamath`

If that sounds good to you, I'll go ahead and mark the fixed errata items and add items for the edits I've made to metamath.tex.

[david-a-wheeler]

In that case, maybe errata.md could also keep track of which issues have already been fixed, by marking them with an asterisk.

Actually I think the ones that are NOT fixed in the github version should be marked, because we should very quickly get to the point where the GitHub version fixes them all. Then we can remove the explanation about the asterisk (since it is no longer needed).

In my mind, the "errata" are primarily for those who are using the current edition of the book. In the GitHub version I'd prefer to just fix it :-).

[amackay]

I've pushed another commit, which updates errata.md to mention the changes I've made, and marks unfixed errata with an asterisk. Sorry for single-handedly doubling the length of errata.md :P

[benjub]

It should also be an en-dash ("--" in LaTeX).

[aaronpuchert]

Wikipedia says it's Ok either way:

A distinction is often made between "simple" attributive compounds (written with a hyphen) and other subtypes (written with an en dash); at least one authority considers name pairs, where the paired elements carry equal weight, as in the Taft–Hartley Act to be "simple", while others consider an en dash appropriate in instances such as these to represent the parallel relationship, as in the McCain–Feingold bill or Bose–Einstein statistics. When an act of the U.S. Congress is named using the surnames of the senator and representative who sponsored it, the hyphen-minus is used in the short title; thus the short title of Public Law 111–203 is "The Dodd-Frank Wall Street Reform and Consumer Protection Act", with a hyphen-minus rather than an en dash between "Dodd" and "Frank". However, there is a difference between something named for a parallel/coordinate relationship between two people (for example, Satyendra Nath Bose and Albert Einstein) and something named for a single person who had a compound surname, which may be written with a hyphen or a space but not an en dash (for example, the Lennard-Jones potential [hyphen] is named after one person (Mr. John Lennard-Jones), as are Bence Jones proteins and Hughlings Jackson syndrome). Copyeditors use dictionaries (general, medical, biographical, and geographical) to confirm the eponymity (and thus the styling) for specific terms, given that no one can know them all offhand.

Preference for an en dash instead of a hyphen in these coordinate/relationship/connection types of terms is a matter of style, not inherent orthographic "correctness"; both are equally "correct", and each is the preferred style in some style guides. For example, the American Heritage Dictionary of the English Language, the AMA Manual of Style, and Dorland's medical reference works use hyphens, not en dashes, in coordinate terms (such as "blood-brain barrier"), in eponyms (such as "Cheyne-Stokes respiration", "Kaplan-Meier method"), and so on.

[benjub]

Tarski--Grothendieck