learnlatex · davidcarlisle · Jul 25, 2020 · Jul 25, 2020 · Jul 25, 2020 · Jul 25, 2020
diff --git a/en/lesson-01.md b/en/lesson-01.md
@@ -2,7 +2,7 @@
 title: "What is LaTeX and how does it work?"
 ---
 
-Unlike common word processors such as Microsoft Word or LibreOffice, LaTeX
+Unlike common word processors such as Microsoft Word or LibreOffice Writer, LaTeX
 usually does not provide WYSIWYG ('What You See Is What You Get'). With LaTeX
 one takes plain text and enriches it with markup. This markup tells LaTeX
 about the logical meaning of certain elements of the text, similar to the way

diff --git a/en/lesson-05.md b/en/lesson-05.md
@@ -78,14 +78,14 @@ The American Mathematical Society provide variants of the standard
 classes (`amsart`, `amsbook`) with a more traditional design closer to
 that used in mathematics journal publications.
 
-The two largest and most popular 'extended' classes are the KOMA-script bundle
-and the memoir class. KOMA-Scipt offers a set of classes which 'parallel' the
+The two largest and most popular 'extended' classes are the KOMA-Script bundle
+and the memoir class. KOMA-Script offers a set of classes which 'parallel' the
 standard ones: `scrartcl`, `scrreprt` and `scrbook`, while there is a single
 `memoir` class that is most like an extension of `book`.
 
 These extended classes have lots of customisation hooks, which we'll explore a
 bit in an exercise. You might wonder how we can know about the hooks they
-provide; we will cover that [in the last lesson](lesson-15), but you can always
+provide; we will cover that [in a later lesson](lesson-15), but you can always
 jump ahead!
 
 ## Presentations

diff --git a/en/lesson-07.md b/en/lesson-07.md
@@ -116,7 +116,7 @@ rather than the `center` environment. Inside a float, you should use
 `\centering` if you want to horizontally center content; this avoids both
 the float and `center` environment adding extra vertical space.
 
-## Exercise
+## Exercises
 
 Try including an image you have created, replacing the 'standard' ones we have
 used in the demonstration.

diff --git a/en/lesson-10.md b/en/lesson-10.md
@@ -49,7 +49,7 @@ sign the `... $-2$ ...` may use math digits which may not be the same
 font as the text digits (depending on the document class).
 Conversely
 beware of math mode constructs appearing in plain text copied from
-elsewhere such as  monetary values using `$` or filenames using` _` (which
+elsewhere such as  monetary values using `$` or filenames using `_` (which
 may be marked up as `\$` and `\_` respectively).
 
 We can easily add superscripts and subscripts; these are marked using `^` and
@@ -253,7 +253,8 @@ able to guess the names.
 Experiment with the font changing commands: what happens when you try to
 nest them?
 
-Displayed math is centered by default; try adding the `[fleqn]` (flush
+Displayed math is centered by default; try adding the document class
+option `[fleqn]` (flush
 left equation) option to some of the above examples to see a different
 layout. Similarly equation numbers are usually on the
 right. Experiment with adding the `[leqno]` (left equation numbers)

diff --git a/en/lesson-15.md b/en/lesson-15.md
@@ -27,20 +27,20 @@ operable program or batch file.
 ```
 {: .noedit :}
 
-on windows or
+no Windows or
 
 ```
 bash: pdflatex: command not found
 ```
 {: .noedit :}
 
-on linux.
+on Linux.
 
 This is
 not a TeX error but an operating system error saying that TeX is not
 installed or not found.  A common mistake is to install an _editor_
 such as TeXworks or TeXShop but without installing a TeX system such as
-TeX Live or MikTeX.
+TeX Live or MiKTeX.
 
 ## Anatomy of a {{ site.tex }} error message
 

diff --git a/en/more-03.md b/en/more-03.md
@@ -21,7 +21,7 @@ or
 `pdflatex first.tex`
 
 to typeset your PDF. Notice that the `.tex` extension is optional: LaTeX will
-assume files end with`.tex` unless you specify otherwise.
+assume files end with `.tex` unless you specify otherwise.
 
 ## Special characters
 

diff --git a/en/more-06.md b/en/more-06.md
@@ -42,9 +42,9 @@ can 'see' this list. So to pass the language of a document to all packages,
 we might use:
 
 ```latex
-\documentclass[ngerman]{article}
+\documentclass[ngerman]{article} % Notice that the option name is 'ngerman'
 
-\usepackage{babel} % Notice that the option name is 'ngerman'
+\usepackage{babel}
 
 \begin{document}
 

diff --git a/en/more-08.md b/en/more-08.md
@@ -459,7 +459,7 @@ Two & A different long text set in a narrow paragraph, with some more  hard to h
 
 ## Defining new column types
 
-As demonstrated in the main lesson, the array package allows
+As demonstrated in the [main lesson](lesson-08), the `array` package allows
 constructs such as `>{\bfseries}c`  to denote a bold centered column.
 It is often convenient to define a new column type to encapsulate such
 use, for example

diff --git a/en/more-10.md b/en/more-10.md
@@ -3,7 +3,7 @@ title: "More on: Mathematics"
 ---
 
 
-## Further amsmath alignments
+## Further `amsmath` alignments
 
 In addition to the `align*` environment shown in the main lesson,
 `amsmath` has several other display math constructs, notably `gather`
@@ -101,7 +101,7 @@ c&=d
 \end{document}
 ```
 
-# Bold Math
+## Bold Math
 Standard LaTeX has two methods to give bold symbols in math. To make
 an entire expression bold, use `\boldmath` before entering the
 expression. The command `\mathbf` is also available to set individual
@@ -125,7 +125,7 @@ $\mathbf{\pi} r^2$ % bad use of \mathbf
 If you want to access bold symbols (as would be used by `\boldmath`)
 within an otherwise normal weight expression, then you can use the
 command `\bm` from the `bm` package. Note that `\bm` also works with
-symbols such as = and Greek letters. (Note that `\mathbf` has no effect
+symbols such as `=` and Greek letters. (Note that `\mathbf` has no effect
 on `\pi` in the example above.)
 
 ```latex
@@ -143,7 +143,7 @@ $\alpha + \bm{\alpha} < \beta + \bm{\beta}$
 \end{document}
 ```
 
-# Mathtools
+## Mathtools
 The package `mathtools` loads `amsmath` and adds several additional
 features, such as variants of the `amsmath` matrix environments that
 allow the column alignment to be specified.
@@ -164,7 +164,7 @@ allow the column alignment to be specified.
 \end{document}
 ```
 
-# Unicode Math
+## Unicode Math
 
 As will be seen in [Lesson 14](lesson-14), there are variant TeX
 engines that use OpenType fonts. By default, these engines still use

diff --git a/en/more-16.md b/en/more-16.md
@@ -5,18 +5,19 @@ title: "More on: Accessing documentation and getting help"
 
 ## Documented sources of {{site.latex}}
 
-The `texdoc` command described earlier is not restricted to package sources. If you wish to
+The `texdoc` command described earlier is not restricted to package documentation. If you wish to
 go beyond the areas covered by this course and study the LaTeX inplementation in detail then
 the following links may help.
 
-The source of LaTeX itself is available as a LaTeX-typeset document `source2e.pdf`, available at
+The source of LaTeX itself is available as a LaTeX-typeset document `source2e.pdf`, available
+from `texdoc source2e` or at
 [texdoc.net](https://texdoc.net/pkg/source2e)
 
 Current releases of LaTeX also have preloaded the LaTeX3 Programming Language code, previously available
 as the `expl3` package.  `texdoc` may be used to see the
-[expl3 interface description](http://texdoc.net/pkg/interface3)
+[expl3 interface description](http://texdoc.net/pkg/interface3) (`texdoc interface3`)
 or
-[full expl3 source code](http://texdoc.net/pkg/source3).
+[full expl3 source code](http://texdoc.net/pkg/source3) (`texdoc source3`).
 
 
 

diff --git a/pt/extra-01.md b/pt/extra-01.md
@@ -1,4 +1,205 @@
 ---
-title: "Exemplos para mais estudos"
+title: "Exemplos para estudo adicional"
 ---
-Translation to be added _after_ English text completed.
+
+Este curso deu uma visão geral das funcionalidades básicas do LaTeX e alguns
+pacotes fundamentais.  O LaTeX conta com uma vasta biblioteca de pacotes de
+extensão e é usado em muitas áreas.  Aqui daremos alguns exemplos, sem qualquer
+explicação mas com links para a documentação dos respectivos pacotes no
+[texdoc.net](https://texdoc.net).
+Os exemplos foram retirados da documentação dos pacotes exceto onde dito o
+contrário.
+
+**Note** que a inclusão aqui não significa endosso de um pacote específico sobre
+  outros similares;  está página é apenas uma amostra de áreas não abordadas
+  neste curso.
+
+## Química
+
+### [`mhchem`](https://texdoc.net/pkg/mhchem)
+
+```latex
+\documentclass{article}
+\usepackage{mhchem}
+\begin{document}
+\ce{Hg^2+ ->[I-] HgI2 ->[I-] [Hg^{II}I4]^2-}
+\end{document}
+```
+
+## Linguística
+### [`forest`](https://texdoc.net/pkg/forest)
+```latex
+\documentclass{article}
+\usepackage{forest}
+\begin{document}
+\begin{forest}
+[VP
+  [DP[John]]
+  [V’
+    [V[sent]]
+    [DP[Mary]]
+    [DP[D[a]][NP[letter]]]
+  ]
+]
+\end{forest}
+\end{document}
+```
+
+## Xadrez
+
+<!-- not 2017 -->
+### [`xskak`](https://texdoc.net/pkg/xskak)
+```latex
+\documentclass{article}
+\usepackage{xskak}
+\begin{document}
+\newchessgame
+\mainline{1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6}
+
+\xskakset{moveid=2w}%
+\chessboard[setfen=\xskakget{nextfen}]\\[1ex]
+Position after 2.\,\xskakget{lan}
+\end{document}
+```
+
+
+## Poesia
+
+### [`memoir`](https://texdoc.net/pkg/memoir)
+
+
+```latex
+\documentclass{memoir}
+\begin{document}
+\settowidth{\versewidth}{Nay, nay, I leave thee not,
+                                       thou goest too}
+\begin{verse}[\versewidth]
+\ldots \\*
+His judgement rendered, he dissolved the Thing. \\*
+\flagverse{Ingeborg} And your decision? \\*
+\flagverse{Fridthjof} \vinphantom{And your decision?}
+
+                                   Have I ought to choose? \\*
+Is not mine honour bound by his decree? \\*
+And that I will redeem through Angantyr \\*
+His paltry gold doth hide in Nastrand’s flood. \\*
+Today will I depart. \\*
+\flagverse{Ingeborg} \vinphantom{Today will I depart.}
+
+                                 And Ingeborg leave? \\*
+\flagverse{Fridthjof} Nay, nay, I leave thee not,
+
+                                   thou goest too. \\*
+\flagverse{Ingeborg} Impossible! \\*
+\flagverse{Fridthjof} \vinphantom{Impossible!}
+
+                                   O! hear me, ere thou answerest.
+\end{verse}
+\end{document}
+```
+
+## Desenho
+<!-- not 2017 -->
+### [`tikz`](https://texdoc.net/pkg/tikz)
+
+
+<!-- {% raw %} -->
+```latex
+\documentclass{article}
+\usepackage{tikz}
+\usetikzlibrary {perspective}
+
+\begin{document}
+
+\newcommand\simplecuboid[3]{%
+\fill[gray!80!white] (tpp cs:x=0,y=0,z=#3)
+-- (tpp cs:x=0,y=#2,z=#3)
+-- (tpp cs:x=#1,y=#2,z=#3)
+-- (tpp cs:x=#1,y=0,z=#3) -- cycle;
+x
+\fill[gray] (tpp cs:x=0,y=0,z=0)
+-- (tpp cs:x=0,y=0,z=#3)
+-- (tpp cs:x=0,y=#2,z=#3)
+-- (tpp cs:x=0,y=#2,z=0) -- cycle;
+\fill[gray!50!white] (tpp cs:x=0,y=0,z=0)
+-- (tpp cs:x=0,y=0,z=#3)
+-- (tpp cs:x=#1,y=0,z=#3)
+-- (tpp cs:x=#1,y=0,z=0) -- cycle;}
+\newcommand{\simpleaxes}[3]{%
+\draw[->] (-0.5,0,0) -- (#1,0,0) node[pos=1.1]{x};
+\draw[->] (0,-0.5,0) -- (0,#2,0) node[pos=1.1]{y};
+\draw[->] (0,0,-0.5) -- (0,0,#3) node[pos=1.1]{z};}
+\begin{tikzpicture}[3d view]
+   \simplecuboid{2}{2}{2}
+   \simpleaxes{2}{2}{2}
+\end{tikzpicture}
+\end{document}
+```
+<!-- {% endraw %} -->
+
+## Plotagem de funções
+### [`pgfplots`](https://texdoc.net/pkg/plots)
+
+
+<!-- {% raw %} -->
+```latex
+\documentclass{article}
+\usepackage{pgfplots}
+\pgfplotsset{width=7cm,compat=1.17}
+
+\begin{document}
+
+\begin{tikzpicture}
+\begin{axis}[]
+      % density of Normal distribution:
+      \addplot [
+            red,
+            domain=-3e-3:3e-3,
+            samples=201,
+      ]
+            {exp(-x^2 / (2e-3^2)) / (1e-3 * sqrt(2*pi))};
+\end{axis}
+\end{tikzpicture}
+
+\end{document}
+```
+<!-- {% endraw %} -->
+
+## Música
+
+
+### [`musixtex`](https://texdoc.net/pkg/musixtex)
+
+
+<!-- {% raw %} -->
+```latex
+\documentclass{article}
+\usepackage{musixtex}
+
+\begin{document}
+
+\begin{music}
+\parindent10mm
+\instrumentnumber{1}
+% a single instrument
+\setname1{Piano}
+% whose name is Piano
+\setstaffs1{2}
+% with two staffs
+\generalmeter{\meterfrac44}
+% 4/4 meter chosen
+\startextract
+% starting real score
+\Notes\ibu0f0\qb0{cge}\tbu0\qb0g|\hl j\en
+\Notes\ibu0f0\qb0{cge}\tbu0\qb0g|\ql l\sk\ql n\en
+\bar
+\Notes\ibu0f0\qb0{dgf}|\qlp i\en
+\notes\tbu0\qb0g|\ibbl1j3\qb1j\tbl1\qb1k\en
+\Notes\ibu0f0\qb0{cge}\tbu0\qb0g|\hl j\en
+\zendextract
+% terminate excerpt
+\end{music}
+
+\end{document}
+```
+<!-- {% endraw %} -->