[book-dp1] Chapter 9 HTML/PDF comparison issues

[Chihiro2000GitHub]

Hi @mmcky @jstac

Below is an issue I found while comparing the PDF and the HTML in Chapter 9.

1. Duplicated “in” after Proposition 9.2.5

There is a typo that appears in both the PDF and the HTML.

In the paragraph immediately after Proposition 9.2.5, the last sentence currently reads:

Proposition 9.2.5 is proved in in Section B.4.

There seems to be a duplicated “in”. It should probably read:

Proposition 9.2.5 is proved in Section B.4.

HTML:

PDF:

[mmcky]

Thanks @Chihiro2000GitHub — confirmed, and you're right that this is a genuine source typo (it appears in both the PDF and the HTML).

Verified. The source at book/ch_adps.tex:572 reads:

Proposition~\ref{p:fbkc} is proved in in \S\ref{sss:port}.

where \ref{p:fbkc} resolves to Proposition 9.2.5 and \S\ref{sss:port} to Section B.4 — matching exactly what you reported. This is the only " in in " in the book; everywhere else the idiom is a single "in" (e.g. the parallel sentence at book/ch_adps.tex:444).

Triage. This is a LaTeX source typo, not a conversion artifact — the PDF renders directly from the source and the converter faithfully copies the prose, which is why it shows in both outputs. So there's nothing to change in the converter or renderer; the fix belongs in the .tex source and corrects both PDF and HTML.

Fix. Tracked in QuantEcon/book-dp1#370 with PR QuantEcon/book-dp1#371 (removes the duplicated word, regenerates the HTML output), awaiting @jstac's review since it touches the book source.

[Chihiro2000GitHub]

Thanks @mmcky for the quick reply and for taking care of this!

[jstac]

Thanks @mmcky @Chihiro2000GitHub

@mmcky , please feel free to correct clear typos that appear in the tex file.

The best option would be an end-to-end AI pass over the tex files looking for typos. I suppose there will be some judgement calls, so i might need to do this 😬