small fixes to SCP paper

2019-07-19 00:16:31 +01:00 · 2019-07-19 00:16:31 +01:00 · 6b1e3eb69b
commit 6b1e3eb69b
parent 253f5a618c 56ca94be1b
29 changed files with 225 additions and 216 deletions
--- a/.travis.yml
+++ b/.travis.yml
@ -36,6 +36,7 @@ before_install:
 - make travis-setup

 script:
+- curl -L https://raw.githubusercontent.com/MestreLion/git-tools/master/git-restore-mtime | python
 - agda --version
 - acknowledgements --version
 - make test-offline # disable to only build cache
--- a/26
+++ b/26
@ -14,12 +14,19 @@ endif

 # Build PLFA and test hyperlinks
 test: build
-	ruby -S bundle exec htmlproofer _site
+	ruby -S bundle exec htmlproofer '_site'


 # Build PLFA and test hyperlinks offline
 test-offline: build
-	ruby -S bundle exec htmlproofer _site --disable-external
+	ruby -S bundle exec htmlproofer '_site' --disable-external
+
+
+# Build PLFA and test hyperlinks for stable
+test-stable-offline: $(MARKDOWN)
+	ruby -S bundle exec jekyll clean
+	ruby -S bundle exec jekyll build --destination '_site/stable' --baseurl '/stable'
+	ruby -S bundle exec htmlproofer '_site' --disable-external


 statistics:
@ -39,11 +46,10 @@ $$(out) : out = $(subst courses/,out/,$(subst src/,out/,$(subst .lagda.md,.md,$(
 $$(out) : $$(in) | out/
 	@echo "Processing $$(subst ./,,$$(in))"
 ifeq (,$$(findstring courses/,$$(in)))
-	./highlight.sh $$(in) --include-path=src/
+	./highlight.sh $$(subst ./,,$$(in)) --include-path=src/
 else
 # Fix links to the file itself (out/<filename> to out/<filepath>)
-	./highlight.sh $$(in) --include-path=src/ --include-path=$$(dir $$(in))
-	@sed -i 's|out/$$(notdir $$(out))|$$(subst ./,,$$(out))|g' $$(out)
+	./highlight.sh $$(subst ./,,$$(in)) --include-path=src/ --include-path=$$(subst ./,,$$(dir $$(in)))
 endif
 endef

@ -66,26 +72,18 @@ server-stop:


 # Build website using jekyll
-build: AGDA2HTML_FLAGS += --link-to-agda-stdlib=$(AGDA_STDLIB_URL)
 build: $(MARKDOWN)
 	ruby -S bundle exec jekyll build


-# Build website using jekyll offline
-build-offline: $(MARKDOWN)
-	ruby -S bundle exec jekyll build
-
-
 # Build website using jekyll incrementally
-build-incremental: AGDA2HTML_FLAGS += --link-to-agda-stdlib
 build-incremental: $(MARKDOWN)
 	ruby -S bundle exec jekyll build --incremental


 # Remove all auxiliary files
 clean:
-	rm -f .agda-stdlib.sed
-	rm -f .links-*.sed
+	rm -f .agda-stdlib.sed .links-*.sed
 ifneq ($(strip $(AGDAI)),)
 	rm $(AGDAI)
 endif
--- a/README.md
+++ b/README.md
@ -58,7 +58,6 @@ The Makefile offers more than just these options:

    make                      (see make test)
    make build                (builds lagda->markdown and the website)
-    make build-offline        (builds lagda->markdown and the website offline)
    make build-incremental    (builds lagda->markdown and the website incrementally)
    make test                 (checks all links are valid)
    make test-offline         (checks all links are valid offline)
@ -80,19 +79,6 @@ unzip, and from within the directory run
    bundle exec jekyll serve


-## GNU sed and macOS
-
-The version of sed that ships with macOS is not fully compatible with the GNU sed.
-Therefore, you may get errors such as:
-```
-sed: 1: "out/plfa/Bisimulation.md": invalid command code o
-```
-You can fix this error by installing a GNU compatible version of sed, e.g. using [Homebrew](https://brew.sh/):
-```
-brew install gnu-sed --with-default-names
-```
-
-
 ## Unicode characters

 If you're having trouble typing the Unicode characters into Emacs, the end of
--- a/_includes/script.html
+++ b/_includes/script.html
@ -1,8 +1,14 @@
 <!-- Import jQuery -->
 <script type="text/javascript" src="{{ "/assets/jquery.js" | prepend: site.baseurl }}"></script>

-<!-- Script which allows for foldable code blocks -->
 <script type="text/javascript">
+
+ // Makes sandwhich menu works
+ $('.menu-icon').click(function(){
+   $('.trigger').toggle();
+ });
+
+ // Script which allows for foldable code blocks
 $('div.foldable pre').each(function(){
     var autoHeight = $(this).height();
     var lineHeight = parseFloat($(this).css('line-height'));
--- a/_posts/2019-07-12-changes-to-plfa.md
+++ b/_posts/2019-07-12-changes-to-plfa.md
@ -5,7 +5,7 @@ title  : "Changes to PLFA – Migration to Agda 2.6"

 Today, we made several major changes to the PLFA infrastructure!

-We upgraded to [Agda 2.6.0.1](https://github.com/agda/agda/releases/tag/v2.6.0.1) and [version 1.1 of the standard library](https://github.com/agda/agda-stdlib/releases/tag/v1.1). If you want to continue working with the book, you'll have to update your versions locally. Please follow the instructions in [Getting Started](/GettingStarted/) to reinstall Agda and the standard library.
+We upgraded to [Agda 2.6.0.1](https://github.com/agda/agda/releases/tag/v2.6.0.1) and [version 1.1 of the standard library](https://github.com/agda/agda-stdlib/releases/tag/v1.1). If you want to continue working with the book, you'll have to update your versions locally. Please follow the instructions in [Getting Started]({{ site.baseurl }}/GettingStarted/) to reinstall Agda and the standard library.

 We deprecated [agda2html](https://github.com/wenkokke/agda2html). In version 2.6, Agda has added support for the `--html-highlight` flag. Using this command, Agda will highlight only the code in a file, and leave the rest untouched:
 ```bash
--- a/_sass/agda.scss
+++ b/_sass/agda.scss
@ -1,8 +1,8 @@
 // Define variables for code formatting
@font-face {
-    font-family: 'Dejavu Sans Mono';
-    src: url('fonts/DejavuSansMono.woff2') format('woff2'),
-         url('fonts/DejavuSansMono.woff') format('woff');
+    font-family: 'DejaVu Sans Mono';
+    src: url('fonts/DejaVuSansMono.woff2') format('woff2'),
+         url('fonts/DejaVuSansMono.woff') format('woff');
    font-weight: normal;
    font-style: normal;

@ -16,7 +16,7 @@
 }

@mixin code-font {
-    font-family: 'Dejavu Sans Mono', 'Source Code Pro', 'Bitstream Vera Sans Mono', 'FreeMono', 'Courier New', 'Monaco', 'Menlo', monospace, serif;
+    font-family: 'DejaVu Sans Mono', 'Source Code Pro', 'Bitstream Vera Sans Mono', 'FreeMono', 'Courier New', 'Monaco', 'Menlo', monospace, serif;
    font-size: .85em;
 }
@mixin code-container {
--- a/assets/main.scss
+++ b/assets/main.scss
@ -4,3 +4,11 @@
@import "katex";
@import "minima";
@import "agda";
+
+$on-medium: 600px !default;
+
+.trigger { display: none; }
+
+@media screen and (min-width: $on-medium) {
+  .trigger { display: block; }
+}
--- a/courses/padova/2019/padova2019.md
+++ b/courses/padova/2019/padova2019.md
@ -1,7 +1,7 @@
 ---
 title     : "Padova: Course notes"
 layout    : page
-permalink : /Padova/
+permalink : /Padova/2019/
 ---

 ## Staff
@ -20,20 +20,20 @@ permalink : /Padova/
 <table>
 <tr>
  <td><b>Wed 28 May</b></td>
-  <td><a href="/Naturals/">Naturals</a>,
-      <a href="/Induction/">Induction</a> &amp; <a href="/Relations/">Relations</a></td>
+  <td><a href="{{ site.baseurl }}/Naturals/">Naturals</a>,
+      <a href="{{ site.baseurl }}/Induction/">Induction</a> &amp; <a href="{{ site.baseurl }}/Relations/">Relations</a></td>
 </tr>
 <tr>
  <td><b>Thu 29 May</b></td>
-  <td><a href="/Lambda/">Lambda</a> &amp;
-      <a href="/Properties/">Properties</a></td>
+  <td><a href="{{ site.baseurl }}/Lambda/">Lambda</a> &amp;
+      <a href="{{ site.baseurl }}/Properties/">Properties</a></td>
 </tr>
 </table>


 ## Assignments

-For instructions on how to set up Agda for PLFA see [Getting Started](/GettingStarted/).
+For instructions on how to set up Agda for PLFA see [Getting Started]({{ site.baseurl }}/GettingStarted/).

 * Wed 28 May
   - Naturals (`_^_`)
--- a/courses/puc/2019/puc2019.md
+++ b/courses/puc/2019/puc2019.md
@ -21,15 +21,15 @@ Lectures and tutorials take place Fridays and some Thursdays in 548L.
 <table>
 <tr>
  <td><b>Fri 29 Mar</b></td>
-  <td><a href="/Naturals/">Naturals</a></td>
+  <td><a href="{{ site.baseurl }}/Naturals/">Naturals</a></td>
 </tr>
 <tr>
  <td><b>Fri 5 Apr</b></td>
-  <td><a href="/Induction/">Induction</a> &amp; <a href="/Relations/">Relations</a></td>
+  <td><a href="{{ site.baseurl }}/Induction/">Induction</a> &amp; <a href="{{ site.baseurl }}/Relations/">Relations</a></td>
 </tr>
 <tr>
  <td><b>Thu 11 Apr</b></td>
-  <td><a href="/Relations/">Relations</a></td>
+  <td><a href="{{ site.baseurl }}/Relations/">Relations</a></td>
 </tr>
 <tr>
  <td><b>Fri 19 Apr</b></td>
@ -37,16 +37,16 @@ Lectures and tutorials take place Fridays and some Thursdays in 548L.
 </tr>
 <tr>
  <td><b>Fri 26 Apr</b></td>
-  <td><a href="/Equality/">Equality</a> &amp;
-      <a href="/Isomorphism/">Isomorphism</a> &amp;
-      <a href="/Connectives/">Connectives</a></td>
+  <td><a href="{{ site.baseurl }}/Equality/">Equality</a> &amp;
+      <a href="{{ site.baseurl }}/Isomorphism/">Isomorphism</a> &amp;
+      <a href="{{ site.baseurl }}/Connectives/">Connectives</a></td>
 </tr>
 <tr>
  <td><b>Fri 3 May</b></td>
-  <td><a href="/Negation/">Negation</a> &amp;
-      <a href="/Quantifiers/">Quantifiers</a> &amp;
-      <a href="/Decidable/">Decidable</a> &amp;
-      <a href="/Lists/">Lists</a></td>
+  <td><a href="{{ site.baseurl }}/Negation/">Negation</a> &amp;
+      <a href="{{ site.baseurl }}/Quantifiers/">Quantifiers</a> &amp;
+      <a href="{{ site.baseurl }}/Decidable/">Decidable</a> &amp;
+      <a href="{{ site.baseurl }}/Lists/">Lists</a></td>
 </tr>
 <tr>
  <td><b>Fri 10 May</b></td>
@ -58,8 +58,8 @@ Lectures and tutorials take place Fridays and some Thursdays in 548L.
 </tr>
 <tr>
  <td><b>Fri 24 May</b></td>
-  <td><a href="/Lambda/">Lambda</a> &amp;
-      <a href="/Properties/">Properties</a></td>
+  <td><a href="{{ site.baseurl }}/Lambda/">Lambda</a> &amp;
+      <a href="{{ site.baseurl }}/Properties/">Properties</a></td>
 </tr>
 <tr>
  <td><b>Fri 31 May</b></td>
@ -67,8 +67,8 @@ Lectures and tutorials take place Fridays and some Thursdays in 548L.
 </tr>
 <tr>
  <td><b>Fri 7 June</b></td>
-  <td><a href="/DeBruijn/">DeBruijn</a> &amp;
-      <a href="/More/">More</a></td>
+  <td><a href="{{ site.baseurl }}/DeBruijn/">DeBruijn</a> &amp;
+      <a href="{{ site.baseurl }}/More/">More</a></td>
 </tr>
 <tr>
  <td><b>Fri 14 June</b></td>
@ -76,8 +76,8 @@ Lectures and tutorials take place Fridays and some Thursdays in 548L.
 </tr>
 <tr>
  <td><b>Fri 21 June</b></td>
-  <td><a href="/Inference/">Inference</a> &amp;
-      <a href="/Untyped/">Untyped</a></td>
+  <td><a href="{{ site.baseurl }}/Inference/">Inference</a> &amp;
+      <a href="{{ site.baseurl }}/Untyped/">Untyped</a></td>
 </tr>
 <tr>
  <td><b>Fri 28 June</b></td>
@ -92,15 +92,15 @@ Lectures and tutorials take place Fridays and some Thursdays in 548L.

 ## Assignments

-For instructions on how to set up Agda for PLFA see [Getting Started](/GettingStarted/).
+For instructions on how to set up Agda for PLFA see [Getting Started]({{ site.baseurl }}/GettingStarted/).

-* [PUC Assignment 1](/PUC/2019/Assignment1/) due Friday 26 April.
-* [PUC Assignment 2](/PUC/2019/Assignment2/) due Wednesday 22 May.
-* [PUC Assignment 3](/PUC/2019/Assignment3/) due Wednesday 5 June.
-* [PUC Assignment 4](/PUC/2019/Assignment4/) due Wednesday 19 June.
-* [PUC Assignment 5](/PUC/2019/Assignment5/) due Tuesday 25 June.
-* [PUC Assignment 6](/courses/tspl/2018/Mock1.pdf) due Tuesday 25 June.
-  Use file [Exam](/PUC/2019/Exam/). Despite the rubric, do **all three questions**.
+* [PUC Assignment 1]({{ site.baseurl }}/PUC/2019/Assignment1/) due Friday 26 April.
+* [PUC Assignment 2]({{ site.baseurl }}/PUC/2019/Assignment2/) due Wednesday 22 May.
+* [PUC Assignment 3]({{ site.baseurl }}/PUC/2019/Assignment3/) due Wednesday 5 June.
+* [PUC Assignment 4]({{ site.baseurl }}/PUC/2019/Assignment4/) due Wednesday 19 June.
+* [PUC Assignment 5]({{ site.baseurl }}/PUC/2019/Assignment5/) due Tuesday 25 June.
+* [PUC Assignment 6]({{ site.baseurl }}/courses/tspl/2018/Mock1.pdf) due Tuesday 25 June.
+  Use file [Exam]({{ site.baseurl }}/PUC/2019/Exam/). Despite the rubric, do **all three questions**.

 Submit assignments by email to [wadler@inf.ed.ac.uk](mailto:wadler@inf.ed.ac.uk).
 Attach a single file named `Assignment1.lagda.md` or the like.  Include
--- a/courses/tspl/2018/tspl2018.md
+++ b/courses/tspl/2018/tspl2018.md
@ -27,51 +27,51 @@ Lectures take place Monday, Wednesday, and Friday in AT 7.02. (Moved from AT 5.0
 </tr>
 <tr>
  <td>1</td>
-  <td><b>17 Sep</b> <a href="/Naturals/">Naturals</a></td>
-  <td><b>19 Sep</b> <a href="/Induction/">Induction</a></td>
-  <td><b>21 Sep</b> <a href="/Induction/">Induction</a></td>
+  <td><b>17 Sep</b> <a href="{{ site.baseurl }}/Naturals/">Naturals</a></td>
+  <td><b>19 Sep</b> <a href="{{ site.baseurl }}/Induction/">Induction</a></td>
+  <td><b>21 Sep</b> <a href="{{ site.baseurl }}/Induction/">Induction</a></td>
 </tr>
 <tr>
  <td>2</td>
-  <td><b>24 Sep</b> <a href="/Relations/">Relations</a> (Chad)</td>
-  <td><b>26 Sep</b> <a href="/Relations/">Relations</a> (Chad)</td>
+  <td><b>24 Sep</b> <a href="{{ site.baseurl }}/Relations/">Relations</a> (Chad)</td>
+  <td><b>26 Sep</b> <a href="{{ site.baseurl }}/Relations/">Relations</a> (Chad)</td>
  <td><b>28 Sep</b> (no class)</td>
 </tr>
 <tr>
  <td>3</td>
-  <td><b>1 Oct</b> <a href="/Equality/">Equality</a> &amp; <a href="/Isomorphism/">Isomorphism</a></td>
-  <td><b>3 Oct</b> <a href="/Connectives/">Connectives</a></td>
-  <td><b>5 Oct</b> <a href="/Negation/">Negation</a></td>
+  <td><b>1 Oct</b> <a href="{{ site.baseurl }}/Equality/">Equality</a> &amp; <a href="{{ site.baseurl }}/Isomorphism/">Isomorphism</a></td>
+  <td><b>3 Oct</b> <a href="{{ site.baseurl }}/Connectives/">Connectives</a></td>
+  <td><b>5 Oct</b> <a href="{{ site.baseurl }}/Negation/">Negation</a></td>
 </tr>
 <tr>
  <td>4</td>
-  <td><b>8 Oct</b> <a href="/Quantifiers/">Quantifiers</a></td>
-  <td><b>10 Oct</b> <a href="/Decidable/">Decidable</a></td>
+  <td><b>8 Oct</b> <a href="{{ site.baseurl }}/Quantifiers/">Quantifiers</a></td>
+  <td><b>10 Oct</b> <a href="{{ site.baseurl }}/Decidable/">Decidable</a></td>
  <td><b>12 Oct</b> (tutorial only)</td>
 </tr>
 <tr>
  <td>5</td>
-  <td><b>15 Oct</b> <a href="/Lists/">Lists</a></td>
+  <td><b>15 Oct</b> <a href="{{ site.baseurl }}/Lists/">Lists</a></td>
  <td><b>17 Oct</b> (tutorial only)</td>
-  <td><b>19 Oct</b> <a href="/Lists/">Lists</a></td>
+  <td><b>19 Oct</b> <a href="{{ site.baseurl }}/Lists/">Lists</a></td>
 </tr>
 <tr>
  <td>6</td>
-  <td><b>22 Oct</b> <a href="/Lambda/">Lambda</a></td>
+  <td><b>22 Oct</b> <a href="{{ site.baseurl }}/Lambda/">Lambda</a></td>
  <td><b>24 Oct</b> (no class)</td>
-  <td><b>26 Oct</b> <a href="/Properties/">Properties</a></td>
+  <td><b>26 Oct</b> <a href="{{ site.baseurl }}/Properties/">Properties</a></td>
 </tr>
 <tr>
  <td>7</td>
-  <td><b>29 Oct</b> <a href="/DeBruijn/">DeBruijn</a></td>
-  <td><b>31 Oct</b> <a href="/More/">More</a></td>
-  <td><b>2 Nov</b> <a href="/Inference/">Inference</a></td>
+  <td><b>29 Oct</b> <a href="{{ site.baseurl }}/DeBruijn/">DeBruijn</a></td>
+  <td><b>31 Oct</b> <a href="{{ site.baseurl }}/More/">More</a></td>
+  <td><b>2 Nov</b> <a href="{{ site.baseurl }}/Inference/">Inference</a></td>
 </tr>
 <tr>
  <td>8</td>
  <td><b>5 Nov</b> (no class)</td>
  <td><b>7 Nov</b> (tutorial only)</td>
-  <td><b>9 Nov</b> <a href="/Untyped/">Untyped</a></td>
+  <td><b>9 Nov</b> <a href="{{ site.baseurl }}/Untyped/">Untyped</a></td>
 </tr>
 <tr>
  <td>9</td>
@ -95,15 +95,15 @@ Lectures take place Monday, Wednesday, and Friday in AT 7.02. (Moved from AT 5.0

 ## Assignments

-For instructions on how to set up Agda for PLFA see [Getting Started](/GettingStarted/).
+For instructions on how to set up Agda for PLFA see [Getting Started]({{ site.baseurl }}/GettingStarted/).

-* [Assignment 1](/TSPL/2018/Assignment1/) cw1 due 4pm Thursday 4 October (Week 3)
-* [Assignment 2](/TSPL/2018/Assignment2/) cw2 due 4pm Thursday 18 October (Week 5)
-* [Assignment 3](/TSPL/2018/Assignment3/) cw3 due 4pm Thursday 1 November (Week 7)
-* [Assignment 4](/TSPL/2018/Assignment4/) cw4 due 4pm Thursday 15 November (Week 9)
-* [Assignment 5](/courses/tspl/2018/Mock1.pdf) cw5 due 4pm Thursday 22 November (Week 10)
+* [Assignment 1]({{ site.baseurl }}/TSPL/2018/Assignment1/) cw1 due 4pm Thursday 4 October (Week 3)
+* [Assignment 2]({{ site.baseurl }}/TSPL/2018/Assignment2/) cw2 due 4pm Thursday 18 October (Week 5)
+* [Assignment 3]({{ site.baseurl }}/TSPL/2018/Assignment3/) cw3 due 4pm Thursday 1 November (Week 7)
+* [Assignment 4]({{ site.baseurl }}/TSPL/2018/Assignment4/) cw4 due 4pm Thursday 15 November (Week 9)
+* [Assignment 5]({{ site.baseurl }}/courses/tspl/2018/Mock1.pdf) cw5 due 4pm Thursday 22 November (Week 10)
  <br />
-  Use file [Exam](/TSPL/2018/Exam/). Despite the rubric, do **all three questions**.
+  Use file [Exam]({{ site.baseurl }}/TSPL/2018/Exam/). Despite the rubric, do **all three questions**.


 Assignments are submitted by running
@ -114,5 +114,5 @@ where N is the number of the assignment.

 ## Mock exam

-Here is the text of the [second mock](/courses/tspl/2018/Mock2.pdf)
-and the exam [instructions](/courses/tspl/2018/Instructions.pdf).
+Here is the text of the [second mock]({{ site.baseurl }}/courses/tspl/2018/Mock2.pdf)
+and the exam [instructions]({{ site.baseurl }}/courses/tspl/2018/Instructions.pdf).
--- a/highlight.sh
+++ b/highlight.sh
@ -2,6 +2,10 @@

 AGDA_STDLIB_SED=".agda-stdlib.sed"

+function sedi {
+    sed --version >/dev/null 2>&1 && sed -i "$@" || sed -i "" "$@"
+}
+
 SRC="$1"
 shift

@ -45,11 +49,18 @@ if [[ ! -f "$HTML" ]]; then
 fi

 # Add source file to the Jekyll metadata
-sed -i "1 s|---|---\nsrc: $SRC|" "$HTML"
+#sedi "1 s|---|---\nsrc: $SRC|" "$HTML"
+ed "$HTML" <<EOF >/dev/null 2>&1
+2i
+src       : "$SRC"
+.
+w
+q
+EOF

 # Add raw tags around Agda code blocks
-sed -i "s|<pre class=\"Agda\">|{% raw %}<pre class=\"Agda\">|" "$HTML"
-sed -i "s|</pre>|</pre>{% endraw %}|" "$HTML"
+sedi "s|<pre class=\"Agda\">|{% raw %}<pre class=\"Agda\">|" "$HTML"
+sedi "s|</pre>|</pre>{% endraw %}|" "$HTML"

 # Fix links to the Agda standard library
 STDLIB_AGDALIB=`grep -m 1 "standard-library" $HOME/.agda/libraries`
@ -76,26 +87,24 @@ if [ ! -f "$AGDA_STDLIB_SED" ]; then
    done
 fi

-sed -i -f "$AGDA_STDLIB_SED" "$HTML"
+sedi -f "$AGDA_STDLIB_SED" "$HTML"

 # Create a sed script which matches and repairs all local links
 for INCLUDE_PATH in "$@"; do
    if [[ "$INCLUDE_PATH" = --include-path=* ]]; then
        INCLUDE_PATH="${INCLUDE_PATH:15}"
        INCLUDE_PATH="${INCLUDE_PATH%/}"
-        INCLUDE_PATH="${INCLUDE_PATH#./}"
        LOCAL_LINKS_SED=`echo ".links-${INCLUDE_PATH}.sed" | sed -e "s|/|-|g;"`

        if [ ! -f "$LOCAL_LINKS_SED" ]; then
            find "$INCLUDE_PATH" -name "*.lagda.md" -print0 | while read -d $'\0' AGDA_MODULE_SRC; do
-                AGDA_MODULE_SRC="${AGDA_MODULE_SRC#./}"
                AGDA_MODULE_OUT="$(out_path "$AGDA_MODULE_SRC")"
                AGDA_MODULE_HTML="$(basename "$(html_path "$AGDA_MODULE_SRC" "$HTML_DIR")" .md).html"
                echo "s|$AGDA_MODULE_HTML|{% endraw %}{{ site.baseurl }}{% link $AGDA_MODULE_OUT %}{% raw %}|;" >> "$LOCAL_LINKS_SED"
            done
        fi

-        sed -i -f "$LOCAL_LINKS_SED" "$HTML"
+        sedi -f "$LOCAL_LINKS_SED" "$HTML"
    fi
 done

--- a/index.md
+++ b/index.md
@ -13,48 +13,48 @@ Pull requests are encouraged.

 ## Front matter

-  - [Dedication](/Dedication/)
-  - [Preface](/Preface/)
+  - [Dedication]({{ site.baseurl }}/Dedication/)
+  - [Preface]({{ site.baseurl }}/Preface/)

 ## Part 1: Logical Foundations

-  - [Naturals](/Naturals/): Natural numbers
-  - [Induction](/Induction/): Proof by induction
-  - [Relations](/Relations/): Inductive definition of relations
-  - [Equality](/Equality/): Equality and equational reasoning
-  - [Isomorphism](/Isomorphism/): Isomorphism and embedding
-  - [Connectives](/Connectives/): Conjunction, disjunction, and implication
-  - [Negation](/Negation/): Negation, with intuitionistic and classical logic
-  - [Quantifiers](/Quantifiers/): Universals and existentials
-  - [Decidable](/Decidable/): Booleans and decision procedures
-  - [Lists](/Lists/): Lists and higher-order functions
+  - [Naturals]({{ site.baseurl }}/Naturals/): Natural numbers
+  - [Induction]({{ site.baseurl }}/Induction/): Proof by induction
+  - [Relations]({{ site.baseurl }}/Relations/): Inductive definition of relations
+  - [Equality]({{ site.baseurl }}/Equality/): Equality and equational reasoning
+  - [Isomorphism]({{ site.baseurl }}/Isomorphism/): Isomorphism and embedding
+  - [Connectives]({{ site.baseurl }}/Connectives/): Conjunction, disjunction, and implication
+  - [Negation]({{ site.baseurl }}/Negation/): Negation, with intuitionistic and classical logic
+  - [Quantifiers]({{ site.baseurl }}/Quantifiers/): Universals and existentials
+  - [Decidable]({{ site.baseurl }}/Decidable/): Booleans and decision procedures
+  - [Lists]({{ site.baseurl }}/Lists/): Lists and higher-order functions

 ## Part 2: Programming Language Foundations

-  - [Lambda](/Lambda/): Introduction to Lambda Calculus
-  - [Properties](/Properties/): Progress and Preservation
-  - [DeBruijn](/DeBruijn/): Inherently typed de Bruijn representation
-  - [More](/More/): Additional constructs of simply-typed lambda calculus
-  - [Bisimulation](/Bisimulation/): Relating reductions systems
-  - [Inference](/Inference/): Bidirectional type inference
-  - [Untyped](/Untyped/): Untyped lambda calculus with full normalisation
+  - [Lambda]({{ site.baseurl }}/Lambda/): Introduction to Lambda Calculus
+  - [Properties]({{ site.baseurl }}/Properties/): Progress and Preservation
+  - [DeBruijn]({{ site.baseurl }}/DeBruijn/): Inherently typed de Bruijn representation
+  - [More]({{ site.baseurl }}/More/): Additional constructs of simply-typed lambda calculus
+  - [Bisimulation]({{ site.baseurl }}/Bisimulation/): Relating reductions systems
+  - [Inference]({{ site.baseurl }}/Inference/): Bidirectional type inference
+  - [Untyped]({{ site.baseurl }}/Untyped/): Untyped lambda calculus with full normalisation

 ## Backmatter

-  - [Acknowledgements](/Acknowledgements/)
-  - [Fonts](/Fonts/): Test page for fonts
-  - [Statistics](/Statistics/): Line counts for each chapter
+  - [Acknowledgements]({{ site.baseurl }}/Acknowledgements/)
+  - [Fonts]({{ site.baseurl }}/Fonts/): Test page for fonts
+  - [Statistics]({{ site.baseurl }}/Statistics/): Line counts for each chapter

 ## Related

  - Courses taught from the textbook:
    * Philip Wadler, University of Edinburgh,
-      [2018](/TSPL/2018/)
+      [2018]({{ site.baseurl }}/TSPL/2018/)
    * David Darais, University of Vermont,
      [2018](http://david.darais.com/courses/fa2018-cs295A/)
    * John Leo, Google Seattle, 2018--2019 
    * Philip Wadler, Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio),
-      [2019](/PUC/2019/)
+      [2019]({{ site.baseurl }}/PUC/2019/)
  - A paper describing the book appeared in [SBMF][sbmf]

 [wen]: https://github.com/wenkokke
--- a/papers/scp/PLFA.tex
+++ b/papers/scp/PLFA.tex
@ -214,9 +214,9 @@ or the SEL4 operating system \citep{Klein-2009,O'Connor-2016}.

 PLFA is aimed at students in the last year of an undergraduate
 honours programme or the first year of a master or doctorate degree.
-It aims to teach the fundamentals of operational semantics of
-programming languages, with simply-typed lambda calculus as the
-central example.  The textbook is written as a literate script in Agda.
+It aims to teach the fundamentals of semantics of
+programming languages, with simply-typed and untyped lambda calculi as the
+central examples.  The textbook is written as a literate script in Agda.
 As with SF, the hope is that using
 a proof assistant will make the development more concrete
 and accessible to students, and give them rapid feedback to find
@ -226,7 +226,7 @@ The book is broken into three parts. The first part, Logical Foundations,
 develops the needed formalisms.  The second part, Programming Language
 Foundations, introduces basic methods of operational semantics.
 The third part, Denotational Semantics, introduces a simple
-model of semantics and its properties.
+model of the lambda calculus and its properties.
 (SF is divided into books, the first two of which have the same names
 as the first two parts of PLFA, and cover similar material.)
 Part~I and Part~II up to Untyped were written by Philip,
@ -435,7 +435,7 @@ SF has a third volume, written by Andrew Appel, on Verified Functional
 Algorithms. We are not sufficiently familiar with that volume to have a view on
 whether it would be easy or hard to cover that material in Agda. And SF recently
 added a fourth volume on random testing of Coq specifications using QuickChick.
-There is currently no tool equivalent to QuickChick available for Agda.
+There is currently no tool equivalent to QuickChick for Agda.

 There is more material that would be desirable to include in PLFA which was not
 due to limits of time, including mutable references, logical relations, System F, and
@ -548,17 +548,17 @@ in inference rules.  The proof of proposition \texttt{progress} (the different
 case making it a distinct name) is layed out carefully. The neat
 indented structure emphasises the case analysis, and all right-hand
 sides line-up in the same column.  Our hope as authors is that students
-will read the formal proof first, and use it as a tabular guide
+read the formal proof first, and use it as a tabular guide
 to the informal explanation that follows.

 SF puts the informal explanation first, followed by the formal proof. The text
 hides the formal proof script under an icon; the figure shows what appears when
 the icon is expanded. As teachers, we were aware that students might skip the
-formal proof on a first reading, and we would have to hope the students would
+formal proof on a first reading, and we have to hope the students 
 return to it and step through it with an interactive tool in order to make it
 intelligible.  We expect the students skipped over many such proofs.  This
 particular proof forms the basis for a question of the mock exam and the past
-exams, so we expect most students will actually look at this one if not all the
+exams, so we expect most students will look at this one if not all the
 others.

 \newcommand{\ex}{\texttt{x}}
@ -596,7 +596,7 @@ provides an interactive development environment of a sort familiar to
 most students.  Interaction in Agda is supported by an Emacs mode.

 In Coq, interaction consists of stepping through a proof script, at
-each point examining the current goal and the variables currently in
+each point examining the current goal and the variables in
 scope, and executing a new command in the script.  Tactics are a whole
 sublanguage, which must be learned in addition to the language for
 expressing specifications.  There are many tactics one can invoke in
@ -619,8 +619,8 @@ An Agda proof consists of typed code.  The interaction is \emph{not}
 recorded.  Students may recreate it by commenting out bits of code and
 introducing a hole in their place.   PLFA contains some prose descriptions
 of interactively building code, but mainly contains code that students
-can read.  They may also introduce holes to interact with the code, but
-we expect this will be rare.
+can read.  They may introduce holes to interact with the code, but
+we expect that will be rare.

 SF encourages students to interact with all the scripts in the text.
 Trying to understand a Coq proof script without running it
@ -931,7 +931,7 @@ language feature.
 Because the course is taught using a proof assistant, it is important
 that students have access to a proof assistant during the exam.
 Students are told in advance that they are expected to get perfect on
-the exam, and that they will have to study hard to achieve this level.
+the exam, and that they will have to study hard to achieve it.
 Given that the goal of formal methods is to avoid error, we believe a
 pedagogical purpose is served by telling the students that they are
 expected to achieve perfection and making it possible for them to do
@ -1000,12 +1000,13 @@ these links, rerouting links to the standard library to the online version, and
 correcting links to local modules.

 (Before the release of Agda 2.6, Agda did not support highlighting embedded
-literate code using HTML.  To address this, we wrote \texttt{agda2html}, a tool
-which rewrote the output of Agda's HTML highlighter to accomplish this. This
-tool had much more functionality, including the fixing of links as outlined
-above, the stripping of implicit arguments to achieve a Haskell-like look, and
-the support for new Markdown constructs for linking to Agda names. However,
-Agda 2.6 has incorporated almost all of this functionality.)
+literate code in HTML.  We maintained \texttt{agda2html}, a tool which rewrites
+the output of Agda's HTML highlighter to highlight embedded code. The tool had
+much more functionality, including the fixing of links as outlined above, the
+stripping of implicit arguments to achieve a Haskell-like look, and the support
+for new Markdown constructs for linking to Agda names. However, Agda 2.6 has
+incorporated almost all of this functionality, and \texttt{agda2html} is now
+deprecated.)

 The book is built, tested, and published after each commit, using Travis CI, a
 web service for continuous integration.  This means that the book is constantly
--- a/src/plfa/Bisimulation.lagda.md
+++ b/src/plfa/Bisimulation.lagda.md
@ -119,14 +119,14 @@ above is a simulation from source to target.  We leave
 establishing it in the reverse direction as an exercise.
 Another exercise is to show the alternative formulations
 of products in
-Chapter [More][plfa.More]
+Chapter [More]({{ site.baseurl }}/More/)
 are in bisimulation.


 ## Imports

 We import our source language from
-Chapter [More][plfa.More]:
+Chapter [More]({{ site.baseurl }}/More/):
 ```
 open import plfa.More
 ```
@ -164,7 +164,7 @@ data _~_ : ∀ {Γ A} → (Γ ⊢ A) → (Γ ⊢ A) → Set where
      ----------------------
    → `let M N ~ (ƛ N†) · M†
 ```
-The language in Chapter [More][plfa.More] has more constructs, which we could easily add.
+The language in Chapter [More]({{ site.baseurl }}/More/) has more constructs, which we could easily add.
 However, leaving the simulation small let's us focus on the essence.
 It's a handy technical trick that we can have a large source language,
 but only bother to include in the simulation the terms of interest.
@ -468,7 +468,7 @@ a bisimulation.
 #### Exercise `products`

 Show that the two formulations of products in
-Chapter [More][plfa.More]
+Chapter [More]({{ site.baseurl }}/More/)
 are in bisimulation.  The only constructs you need to include are
 variables, and those connected to functions and products.
 In this case, the simulation is _not_ lock-step.
--- a/src/plfa/Connectives.lagda.md
+++ b/src/plfa/Connectives.lagda.md
@ -234,7 +234,7 @@ corresponds to `⟨ 1 , ⟨ true , aa ⟩ ⟩`, which is a member of the latter.

 #### Exercise `⇔≃×` (recommended)

-Show that `A ⇔ B` as defined [earlier][plfa.Isomorphism#iff]
+Show that `A ⇔ B` as defined [earlier]({{ site.baseurl }}/Isomorphism/#iff)
 is isomorphic to `(A → B) × (B → A)`.

 ```
@ -770,9 +770,9 @@ The standard library constructs pairs with `_,_` whereas we use `⟨_,_⟩`.
 The former makes it convenient to build triples or larger tuples from pairs,
 permitting `a , b , c` to stand for `(a , (b , c))`.  But it conflicts with
 other useful notations, such as `[_,_]` to construct a list of two elements in
-Chapter [Lists][plfa.Lists]
+Chapter [Lists]({{ site.baseurl }}/Lists/)
 and `Γ , A` to extend environments in
-Chapter [DeBruijn][plfa.DeBruijn].
+Chapter [DeBruijn]({{ site.baseurl }}/DeBruijn/).
 The standard library `_⇔_` is similar to ours, but the one in the
 standard library is less convenient, since it is parameterised with
 respect to an arbitrary notion of equivalence.
--- a/src/plfa/DeBruijn.lagda.md
+++ b/src/plfa/DeBruijn.lagda.md
@ -56,10 +56,10 @@ And here is its corresponding type derivation:
      ∋z = Z

 (These are both taken from Chapter
-[Lambda][plfa.Lambda]
+[Lambda]({{ site.baseurl }}/Lambda/)
 and you can see the corresponding derivation tree written out
 in full
-[here][plfa.Lambda#derivation].)
+[here]({{ site.baseurl }}/Lambda/#derivation).)
 The two definitions are in close correspondence, where:

  * `` `_ `` corresponds to `` ⊢` ``
@ -112,7 +112,7 @@ typed terms, which in context `Γ` have type `A`.
 While these two choices fit well, they are independent.  One
 can use de Bruijn indices in raw terms, or (with more
 difficulty) have inherently typed terms with names.  In
-Chapter [Untyped][plfa.Untyped],
+Chapter [Untyped]({{ site.baseurl }}/Untyped/),
 we will introduce terms with de Bruijn indices that
 are inherently scoped but not typed.

@ -255,7 +255,7 @@ _ : Context
 _ = ∅ , `ℕ ⇒ `ℕ , `ℕ
 ```
 is a context with two variables in scope, where the outer
-bound one has type `` `ℕ → `ℕ ``, and the inner bound one has
+bound one has type `` `ℕ ⇒ `ℕ ``, and the inner bound one has
 type `` `ℕ ``.

 ### Variables and the lookup judgment
@ -320,17 +320,17 @@ with all terms and variable names dropped:
 ```
 data _⊢_ : Context → Type → Set where

-  `_ : ∀ {Γ} {A}
+  `_ : ∀ {Γ A}
    → Γ ∋ A
      ------
    → Γ ⊢ A

-  ƛ_  :  ∀ {Γ} {A B}
+  ƛ_  : ∀ {Γ A B}
    → Γ , A ⊢ B
      ----------
    → Γ ⊢ A ⇒ B

-  _·_ : ∀ {Γ} {A B}
+  _·_ : ∀ {Γ A B}
    → Γ ⊢ A ⇒ B
    → Γ ⊢ A
      ----------
@ -408,7 +408,7 @@ lookup ∅       _        =  ⊥-elim impossible
 We intend to apply the function only when the natural is
 shorter than the length of the context, which we indicate by
 postulating an `impossible` term, just as we did
-[here][plfa.Lambda#impossible].
+[here]({{ site.baseurl }}/Lambda/#impossible).

 Given the above, we can convert a natural to a corresponding
 de Bruijn index, looking up its type in the context:
@ -437,9 +437,9 @@ _ = ƛ ƛ (# 1 · (# 1 · # 0))
 ### Test examples

 We repeat the test examples from
-Chapter [Lambda][plfa.Lambda].
+Chapter [Lambda]({{ site.baseurl }}/Lambda/).
 You can find them
-[here][plfa.Lambda#derivation]
+[here]({{ site.baseurl }}/Lambda/#derivation)
 for comparison.

 First, computing two plus two on naturals:
@ -772,7 +772,7 @@ data Value : ∀ {Γ A} → Γ ⊢ A → Set where

 Here `zero` requires an implicit parameter to aid inference,
 much in the same way that `[]` did in
-[Lists][plfa.Lists].
+[Lists]({{ site.baseurl }}/Lists/).


 ## Reduction
--- a/src/plfa/Decidable.lagda.md
+++ b/src/plfa/Decidable.lagda.md
@ -39,7 +39,7 @@ open import plfa.Isomorphism using (_⇔_)

 ## Evidence vs Computation

-Recall that Chapter [Relations][plfa.Relations]
+Recall that Chapter [Relations]({{ site.baseurl }}/Relations/)
 defined comparison as an inductive datatype,
 which provides _evidence_ that one number
 is less than or equal to another:
@ -548,7 +548,7 @@ postulate
 #### Exercise `iff-erasure` (recommended)

 Give analogues of the `_⇔_` operation from
-Chapter [Isomorphism][plfa.Isomorphism#iff],
+Chapter [Isomorphism]({{ site.baseurl }}/Isomorphism/#iff),
 operation on booleans and decidables, and also show the corresponding erasure:
 ```
 postulate
--- a/src/plfa/Equality.lagda.md
+++ b/src/plfa/Equality.lagda.md
@ -347,7 +347,7 @@ an order that will make sense to the reader.
 #### Exercise `≤-Reasoning` (stretch)

 The proof of monotonicity from
-Chapter [Relations][plfa.Relations]
+Chapter [Relations]({{ site.baseurl }}/Relations/)
 can be written in a more readable form by using an analogue of our
 notation for `≡-Reasoning`.  Define `≤-Reasoning` analogously, and use
 it to write out an alternative proof that addition is monotonic with
--- a/src/plfa/Induction.lagda.md
+++ b/src/plfa/Induction.lagda.md
@ -366,7 +366,7 @@ proof of associativity.

 The symbol `∀` appears in the statement of associativity to indicate that
 it holds for all numbers `m`, `n`, and `p`.  We refer to `∀` as the _universal
-quantifier_, and it is discussed further in Chapter [Quantifiers][plfa.Quantifiers].
+quantifier_, and it is discussed further in Chapter [Quantifiers]({{ site.baseurl }}/Quantifiers/).

 Evidence for a universal quantifier is a function.  The notations

@ -697,11 +697,11 @@ judgments where the first number is less than _m_.
 There is also a completely finite approach to generating the same equations,
 which is left as an exercise for the reader.

-#### Exercise `finite-+-assoc` (stretch) {#finite-plus-assoc}
+#### Exercise `finite-|-assoc` (stretch) {#finite-plus-assoc}

 Write out what is known about associativity of addition on each of the
 first four days using a finite story of creation, as
-[earlier][plfa.Naturals#finite-creation].
+[earlier]({{ site.baseurl }}/Naturals/#finite-creation).

 ```
 -- Your code goes here
@ -927,7 +927,7 @@ for all naturals `n`. Did your proof require induction?
 ```


-#### Exercise `∸-+-assoc` {#monus-plus-assoc}
+#### Exercise `∸-|-assoc` {#monus-plus-assoc}

 Show that monus associates with addition, that is,

@ -954,7 +954,7 @@ for all `m`, `n`, and `p`.
 #### Exercise `Bin-laws` (stretch) {#Bin-laws}

 Recall that
-Exercise [Bin][plfa.Naturals#Bin]
+Exercise [Bin]({{ site.baseurl }}/Naturals/#Bin)
 defines a datatype of bitstrings representing natural numbers
 ```
 data Bin : Set where
--- a/src/plfa/Inference.lagda.md
+++ b/src/plfa/Inference.lagda.md
@ -12,9 +12,9 @@ module plfa.Inference where

 So far in our development, type derivations for the corresponding
 term have been provided by fiat.
-In Chapter [Lambda][plfa.Lambda]
+In Chapter [Lambda]({{ site.baseurl }}/Lambda/)
 type derivations were given separately from the term, while
-in Chapter [DeBruijn][plfa.DeBruijn]
+in Chapter [DeBruijn]({{ site.baseurl }}/DeBruijn/)
 the type derivation was inherently part of the term.

 In practice, one often writes down a term with a few decorations and
@ -27,9 +27,9 @@ inference, which will be presented in this chapter.

 This chapter ties our previous developments together. We begin with
 a term with some type annotations, quite close to the raw terms of
-Chapter [Lambda][plfa.Lambda],
+Chapter [Lambda]({{ site.baseurl }}/Lambda/),
 and from it we compute a term with inherent types, in the style of
-Chapter [DeBruijn][plfa.DeBruijn].
+Chapter [DeBruijn]({{ site.baseurl }}/DeBruijn/).

 ## Introduction: Inference rules as algorithms {#algorithms}

@ -382,7 +382,7 @@ required for `sucᶜ`, which inherits its type as an argument of `plusᶜ`.
 ## Bidirectional type checking

 The typing rules for variables are as in
-[Lambda][plfa.Lambda]:
+[Lambda]({{ site.baseurl }}/Lambda/):
 ```
 data _∋_⦂_ : Context → Id → Type → Set where

@ -456,25 +456,25 @@ data _⊢_↓_ where
    → Γ ⊢ (M ↑) ↓ B
 ```
 We follow the same convention as
-Chapter [Lambda][plfa.Lambda],
+Chapter [Lambda]({{ site.baseurl }}/Lambda/),
 prefacing the constructor with `⊢` to derive the name of the
 corresponding type rule.

 The rules are similar to those in
-Chapter [Lambda][plfa.Lambda],
+Chapter [Lambda]({{ site.baseurl }}/Lambda/),
 modified to support synthesised and inherited types.
 The two new rules are those for `⊢↑` and `⊢↓`.
 The former both passes the type decoration as the inherited type and returns
 it as the synthesised type.  The latter takes the synthesised type and the
 inherited type and confirms they are identical --- it should remind you of
 the equality test in the application rule in the first
-[section][plfa.Inference#algorithms].
+[section]({{ site.baseurl }}/Inference/#algorithms).


 #### Exercise `bidirectional-mul` (recommended) {#bidirectional-mul}

 Rewrite your definition of multiplication from
-Chapter [Lambda][plfa.Lambda], decorated to support inference.
+Chapter [Lambda]({{ site.baseurl }}/Lambda/), decorated to support inference.

 ```
 -- Your code goes here
@ -484,7 +484,7 @@ Chapter [Lambda][plfa.Lambda], decorated to support inference.
 #### Exercise `bidirectional-products` (recommended) {#bidirectional-products}

 Extend the bidirectional type rules to include products from
-Chapter [More][plfa.More].
+Chapter [More]({{ site.baseurl }}/More/).

 ```
 -- Your code goes here
@ -494,7 +494,7 @@ Chapter [More][plfa.More].
 #### Exercise `bidirectional-rest` (stretch)

 Extend the bidirectional type rules to include the rest of the constructs from
-Chapter [More][plfa.More].
+Chapter [More]({{ site.baseurl }}/More/).

 ```
 -- Your code goes here
@ -1004,7 +1004,7 @@ _ = refl
 From the evidence that a decorated term has the correct type it is
 easy to extract the corresponding inherently typed term.  We use the
 name `DB` to refer to the code in
-Chapter [DeBruijn][plfa.DeBruijn].
+Chapter [DeBruijn]({{ site.baseurl }}/DeBruijn/).
 It is easy to define an _erasure_ function that takes evidence of a
 type judgment into the corresponding inherently typed term.

@ -1067,17 +1067,17 @@ _ = refl
 ```
 Thus, we have confirmed that bidirectional type inference
 converts decorated versions of the lambda terms from
-Chapter [Lambda][plfa.Lambda]
+Chapter [Lambda]({{ site.baseurl }}/Lambda/)
 to the inherently typed terms of
-Chapter [DeBruijn][plfa.DeBruijn].
+Chapter [DeBruijn]({{ site.baseurl }}/DeBruijn/).


 #### Exercise `inference-multiplication` (recommended)

 Apply inference to your decorated definition of multiplication from
-exercise [`bidirectional-mul`][plfa.Inference#bidirectional-mul], and show that
+exercise [`bidirectional-mul`]({{ site.baseurl }}/Inference/#bidirectional-mul), and show that
 erasure of the inferred typing yields your definition of
-multiplication from Chapter [DeBruijn][plfa.DeBruijn].
+multiplication from Chapter [DeBruijn]({{ site.baseurl }}/DeBruijn/).

 ```
 -- Your code goes here
@ -1086,7 +1086,7 @@ multiplication from Chapter [DeBruijn][plfa.DeBruijn].
 #### Exercise `inference-products` (recommended)

 Using your rules from exercise
-[`bidirectional-products`][plfa.Inference#bidirectional-products], extend
+[`bidirectional-products`]({{ site.baseurl }}/Inference/#bidirectional-products), extend
 bidirectional inference to include products.

 ```
@ -1096,7 +1096,7 @@ bidirectional inference to include products.
 #### Exercise `inference-rest` (stretch)

 Extend the bidirectional type rules to include the rest of the constructs from
-Chapter [More][plfa.More].
+Chapter [More]({{ site.baseurl }}/More/).

 ```
 -- Your code goes here
--- a/src/plfa/Isomorphism.lagda.md
+++ b/src/plfa/Isomorphism.lagda.md
@ -89,7 +89,7 @@ Extensionality asserts that the only way to distinguish functions is
 by applying them; if two functions applied to the same argument always
 yield the same result, then they are the same function.  It is the
 converse of `cong-app`, as introduced
-[earlier][plfa.Equality#cong].
+[earlier]({{ site.baseurl }}/Equality/#cong).

 Agda does not presume extensionality, but we can postulate that it holds:
 ```
@ -104,7 +104,7 @@ known to be consistent with the theory that underlies Agda.

 As an example, consider that we need results from two libraries,
 one where addition is defined, as in
-Chapter [Naturals][plfa.Naturals],
+Chapter [Naturals]({{ site.baseurl }}/Naturals/),
 and one where it is defined the other way around.
 ```
 _+′_ : ℕ → ℕ → ℕ
@ -456,8 +456,8 @@ Show that equivalence is reflexive, symmetric, and transitive.
 #### Exercise `Bin-embedding` (stretch) {#Bin-embedding}

 Recall that Exercises
-[Bin][plfa.Naturals#Bin] and
-[Bin-laws][plfa.Induction#Bin-laws]
+[Bin]({{ site.baseurl }}/Naturals/#Bin) and
+[Bin-laws]({{ site.baseurl }}/Induction/#Bin-laws)
 define a datatype of bitstrings representing natural numbers:
 ```
 data Bin : Set where
--- a/src/plfa/Lambda.lagda.md
+++ b/src/plfa/Lambda.lagda.md
@ -25,7 +25,7 @@ recursive function definitions.

 This chapter formalises the simply-typed lambda calculus, giving its
 syntax, small-step semantics, and typing rules.  The next chapter
-[Properties][plfa.Properties]
+[Properties]({{ site.baseurl }}/Properties/)
 proves its main properties, including
 progress and preservation.  Following chapters will look at a number
 of variants of lambda calculus.
@ -33,7 +33,7 @@ of variants of lambda calculus.
 Be aware that the approach we take here is _not_ our recommended
 approach to formalisation.  Using de Bruijn indices and
 inherently-typed terms, as we will do in
-Chapter [DeBruijn][plfa.DeBruijn],
+Chapter [DeBruijn]({{ site.baseurl }}/DeBruijn/),
 leads to a more compact formulation.  Nonetheless, we begin with named
 variables, partly because such terms are easier to read and partly
 because the development is more traditional.
@ -138,7 +138,7 @@ plus = μ "+" ⇒ ƛ "m" ⇒ ƛ "n" ⇒
 ```
 The recursive definition of addition is similar to our original
 definition of `_+_` for naturals, as given in
-Chapter [Naturals][plfa.Naturals#plus].
+Chapter [Naturals]({{ site.baseurl }}/Naturals/#plus).
 Here variable "m" is bound twice, once in a lambda abstraction and once in
 the successor branch of the case; the first use of "m" refers to
 the former and the second to the latter.  Any use of "m" in the successor branch
@ -373,7 +373,7 @@ to treat variables as values, and to treat
 `ƛ x ⇒ N` as a value only if `N` is a value.
 Indeed, this is how Agda normalises terms.
 We consider this approach in
-Chapter [Untyped][plfa.Untyped].
+Chapter [Untyped]({{ site.baseurl }}/Untyped/).


 ## Substitution
@ -678,7 +678,7 @@ the reflexive and transitive closure `—↠` of the step relation `—→`.
 We define reflexive and transitive closure as a sequence of zero or
 more steps of the underlying relation, along lines similar to that for
 reasoning about chains of equalities in
-Chapter [Equality][plfa.Equality]:
+Chapter [Equality]({{ site.baseurl }}/Equality/):
 ```
 infix  2 _—↠_
 infix  1 begin_
@ -1310,7 +1310,7 @@ We can fill in `Z` by hand. If we type C-c C-space, Agda will confirm we are don

 The entire process can be automated using Agsy, invoked with C-c C-a.

-Chapter [Inference][plfa.Inference]
+Chapter [Inference]({{ site.baseurl }}/Inference/)
 will show how to use Agda to compute type derivations directly.


--- a/src/plfa/Lists.lagda.md
+++ b/src/plfa/Lists.lagda.md
@ -178,7 +178,7 @@ and follows by straightforward computation combined with the
 inductive hypothesis.  As usual, the inductive hypothesis is indicated by a recursive
 invocation of the proof, in this case `++-assoc xs ys zs`.

-Recall that Agda supports [sections][plfa.Induction#sections].
+Recall that Agda supports [sections]({{ site.baseurl }}/Induction/#sections).
 Applying `cong (x ∷_)` promotes the inductive hypothesis:

    (xs ++ ys) ++ zs ≡ xs ++ (ys ++ zs)
@ -932,7 +932,7 @@ Show that the equivalence `All-++-⇔` can be extended to an isomorphism.
 #### Exercise `¬Any≃All¬` (stretch)

 First generalise composition to arbitrary levels, using
-[universe polymorphism][plfa.Equality#unipoly]:
+[universe polymorphism]({{ site.baseurl }}/Equality/#unipoly):
 ```
 _∘′_ : ∀ {ℓ₁ ℓ₂ ℓ₃ : Level} {A : Set ℓ₁} {B : Set ℓ₂} {C : Set ℓ₃}
  → (B → C) → (A → B) → A → C
--- a/src/plfa/More.lagda.md
+++ b/src/plfa/More.lagda.md
@ -31,10 +31,10 @@ informal. We show how to formalise the first four constructs and leave
 the rest as an exercise for the reader.

 Our informal descriptions will be in the style of
-Chapter [Lambda][plfa.Lambda],
+Chapter [Lambda]({{ site.baseurl }}/Lambda/),
 using named variables and a separate type relation,
 while our formalisation will be in the style of
-Chapter [DeBruijn][plfa.DeBruijn],
+Chapter [DeBruijn]({{ site.baseurl }}/DeBruijn/),
 using de Bruijn indices and inherently typed terms.

 By now, explaining with symbols should be more concise, more precise,
--- a/src/plfa/Naturals.lagda.md
+++ b/src/plfa/Naturals.lagda.md
@ -277,7 +277,7 @@ all the names specified in the `using` clause into the current scope.
 In this case, the names added are `begin_`, `_≡⟨⟩_`, and `_∎`.  We
 will see how these are used below.  We take these as givens for now,
 but will see how they are defined in
-Chapter [Equality][plfa.Equality].
+Chapter [Equality]({{ site.baseurl }}/Equality/).

 Agda uses underbars to indicate where terms appear in infix or mixfix
 operators. Thus, `_≡_` and `_≡⟨⟩_` are infix (each operator is written
--- a/src/plfa/Negation.lagda.md
+++ b/src/plfa/Negation.lagda.md
@ -189,7 +189,7 @@ again causing the equality to hold trivially.
 #### Exercise `<-irreflexive` (recommended)

 Using negation, show that
-[strict inequality][plfa.Relations#strict-inequality]
+[strict inequality]({{ site.baseurl }}/Relations/#strict-inequality)
 is irreflexive, that is, `n < n` holds for no `n`.

 ```
@ -200,7 +200,7 @@ is irreflexive, that is, `n < n` holds for no `n`.
 #### Exercise `trichotomy`

 Show that strict inequality satisfies
-[trichotomy][plfa.Relations#trichotomy],
+[trichotomy]({{ site.baseurl }}/Relations/#trichotomy),
 that is, for any naturals `m` and `n` exactly one of the following holds:

 * `m < n`
--- a/src/plfa/Quantifiers.lagda.md
+++ b/src/plfa/Quantifiers.lagda.md
@ -90,7 +90,7 @@ postulate
    (∀ (x : A) → B x × C x) ≃ (∀ (x : A) → B x) × (∀ (x : A) → C x)
 ```
 Compare this with the result (`→-distrib-×`) in
-Chapter [Connectives][plfa.Connectives].
+Chapter [Connectives]({{ site.baseurl }}/Connectives/).

 #### Exercise `⊎∀-implies-∀⊎`

@ -233,7 +233,7 @@ Indeed, the converse also holds, and the two together form an isomorphism:
 ```
 The result can be viewed as a generalisation of currying.  Indeed, the code to
 establish the isomorphism is identical to what we wrote when discussing
-[implication][plfa.Connectives#implication].
+[implication]({{ site.baseurl }}/Connectives/#implication).

 #### Exercise `∃-distrib-⊎` (recommended)

@ -263,7 +263,7 @@ Show that `∃[ x ] B x` is isomorphic to `B aa ⊎ B bb ⊎ B cc`.
 ## An existential example

 Recall the definitions of `even` and `odd` from
-Chapter [Relations][plfa.Relations]:
+Chapter [Relations]({{ site.baseurl }}/Relations/):
 ```
 data even : ℕ → Set
 data odd  : ℕ → Set
@ -371,7 +371,7 @@ restated in this way.
 -- Your code goes here
 ```

-#### Exercise `∃-+-≤`
+#### Exercise `∃-|-≤`

 Show that `y ≤ z` holds if and only if there exists a `x` such that
 `x + y ≡ z`.
@ -432,9 +432,9 @@ Does the converse hold? If so, prove; if not, explain why.
 #### Exercise `Bin-isomorphism` (stretch) {#Bin-isomorphism}

 Recall that Exercises
-[Bin][plfa.Naturals#Bin],
-[Bin-laws][plfa.Induction#Bin-laws], and
-[Bin-predicates][plfa.Relations#Bin-predicates]
+[Bin]({{ site.baseurl }}/Naturals/#Bin),
+[Bin-laws]({{ site.baseurl }}/Induction/#Bin-laws), and
+[Bin-predicates]({{ site.baseurl }}/Relations/#Bin-predicates)
 define a datatype of bitstrings representing natural numbers:
 ```
 data Bin : Set where
--- a/src/plfa/Relations.lagda.md
+++ b/src/plfa/Relations.lagda.md
@ -155,7 +155,7 @@ either `(1 ≤ 2) ≤ 3` or `1 ≤ (2 ≤ 3)`.
 Given two numbers, it is straightforward to compute whether or not the
 first is less than or equal to the second.  We don't give the code for
 doing so here, but will return to this point in
-Chapter [Decidable][plfa.Decidable].
+Chapter [Decidable]({{ site.baseurl }}/Decidable/).


 ## Inversion
@ -377,7 +377,7 @@ evidence of `m ≤ n` and `n ≤ m` respectively.

 (For those familiar with logic, the above definition
 could also be written as a disjunction. Disjunctions will
-be introduced in Chapter [Connectives][plfa.Connectives].)
+be introduced in Chapter [Connectives]({{ site.baseurl }}/Connectives/).)

 This is our first use of a datatype with _parameters_,
 in this case `m` and `n`.  It is equivalent to the following
@ -572,7 +572,7 @@ It is also monotonic with regards to addition and multiplication.
 Most of the above are considered in exercises below.  Irreflexivity
 requires negation, as does the fact that the three cases in
 trichotomy are mutually exclusive, so those points are deferred to
-Chapter [Negation][plfa.Negation].
+Chapter [Negation]({{ site.baseurl }}/Negation/).

 It is straightforward to show that `suc m ≤ n` implies `m < n`,
 and conversely.  One can then give an alternative derivation of the
@ -599,7 +599,7 @@ Define `m > n` to be the same as `n < m`.
 You will need a suitable data declaration,
 similar to that used for totality.
 (We will show that the three cases are exclusive after we introduce
-[negation][plfa.Negation].)
+[negation]({{ site.baseurl }}/Negation/).)

 ```
 -- Your code goes here
@ -742,7 +742,7 @@ Show that the sum of two odd numbers is even.
 #### Exercise `Bin-predicates` (stretch) {#Bin-predicates}

 Recall that
-Exercise [Bin][plfa.Naturals#Bin]
+Exercise [Bin]({{ site.baseurl }}/Naturals/#Bin)
 defines a datatype `Bin` of bitstrings representing natural numbers.
 Representations are not unique due to leading zeros.
 Hence, eleven may be represented by both of the following:
@ -801,7 +801,7 @@ import Data.Nat.Properties using (≤-refl; ≤-trans; ≤-antisym; ≤-total;
 ```
 In the standard library, `≤-total` is formalised in terms of
 disjunction (which we define in
-Chapter [Connectives][plfa.Connectives]),
+Chapter [Connectives]({{ site.baseurl }}/Connectives/)),
 and `+-monoʳ-≤`, `+-monoˡ-≤`, `+-mono-≤` are proved differently than here,
 and more arguments are implicit.

--- a/src/plfa/Untyped.lagda.md
+++ b/src/plfa/Untyped.lagda.md
@ -62,7 +62,7 @@ open import Relation.Nullary.Product using (_×-dec_)
 ## Untyped is Uni-typed

 Our development will be close to that in
-Chapter [DeBruijn][plfa.DeBruijn],
+Chapter [DeBruijn]({{ site.baseurl }}/DeBruijn/),
 save that every term will have exactly the same type, written `★`
 and pronounced "any".
 This matches a slogan introduced by Dana Scott
@ -756,7 +756,7 @@ Confirm that two times two is four.
 #### Exercise `encode-more` (stretch)

 Along the lines above, encode all of the constructs of
-Chapter [More][plfa.More],
+Chapter [More]({{ site.baseurl }}/More/),
 save for primitive numbers, in the untyped lambda calculus.

 ```