From 8d40127af01105082f6ab9f85d827659c5f6e223 Mon Sep 17 00:00:00 2001
From: citrusmunch <citrusmunch@users.noreply.github.com>
Date: Thu, 24 Oct 2019 21:30:59 -0400
Subject: [PATCH 1/9] consistent variable name typo
---
src/plfa/part1/Relations.lagda.md | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/plfa/part1/Relations.lagda.md b/src/plfa/part1/Relations.lagda.md
index 2d6b7591..9028fa51 100644
--- a/src/plfa/part1/Relations.lagda.md
+++ b/src/plfa/part1/Relations.lagda.md
@@ -773,7 +773,7 @@ if it consists of a single zero (representing zero).
Show that increment preserves canonical bitstrings:
- Can x
+ Can b
------------
Can (inc b)
From 4dd9f2e37e2044dd317b87ff1469ba1510a95809 Mon Sep 17 00:00:00 2001
From: wadler <wadler@inf.ed.ac.uk>
Date: Fri, 25 Oct 2019 18:55:14 +0100
Subject: [PATCH 2/9] Assignment 4
---
courses/tspl/2019/tspl2019.md | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/courses/tspl/2019/tspl2019.md b/courses/tspl/2019/tspl2019.md
index 93ffb328..07471588 100644
--- a/courses/tspl/2019/tspl2019.md
+++ b/courses/tspl/2019/tspl2019.md
@@ -122,7 +122,7 @@ For instructions on how to set up Agda for PLFA see [Getting Started]({{ site.ba
* [Assignment 1]({{ site.baseurl }}/TSPL/2019/Assignment1/) cw1 due 4pm Thursday 3 October (Week 3)
* [Assignment 2]({{ site.baseurl }}/TSPL/2019/Assignment2/) cw2 due 4pm Thursday 17 October (Week 5)
* [Assignment 3]({{ site.baseurl }}/TSPL/2019/Assignment3/) cw3 due 4pm Thursday 31 October (Week 7)
-* Assignment 4 <!-- [Assignment 4]({{ site.baseurl }}/TSPL/2019/Assignment4/) --> cw4 due 4pm Thursday 14 November (Week 9)
+* [Assignment 4]({{ site.baseurl }}/TSPL/2019/Assignment4/) cw4 due 4pm Thursday 14 November (Week 9)
* Assignment 5 <!-- [Assignment 5]({{ site.baseurl }}/courses/tspl/2010/Mock1.pdf) --> cw5 due 4pm Thursday 21 November (Week 10)
<!-- <br />
Use file [Exam]({{ site.baseurl }}/TSPL/2018/Exam/). Despite the rubric, do **all three questions**. -->
From 1f624c0b4562f6f2ed578e6a2aaff87d4ec6e37f Mon Sep 17 00:00:00 2001
From: wadler <wadler@inf.ed.ac.uk>
Date: Sat, 26 Oct 2019 10:10:40 +0100
Subject: [PATCH 3/9] Update year on Assignment 4 link
---
courses/tspl/2019/Assignment4.lagda.md | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/courses/tspl/2019/Assignment4.lagda.md b/courses/tspl/2019/Assignment4.lagda.md
index e1ee7734..81a5b661 100644
--- a/courses/tspl/2019/Assignment4.lagda.md
+++ b/courses/tspl/2019/Assignment4.lagda.md
@@ -1,7 +1,7 @@
---
title : "Assignment4: TSPL Assignment 4"
layout : page
-permalink : /TSPL/2018/Assignment4/
+permalink : /TSPL/2019/Assignment4/
---
```
From 0e1c5d34ea10b0058f93c47f25b539ea03781dc7 Mon Sep 17 00:00:00 2001
From: Pedro Minicz <pedrominicz@gmail.com>
Date: Sat, 26 Oct 2019 14:56:56 -0300
Subject: [PATCH 4/9] Fix: make capitalization consistent.
---
src/plfa/part1/Lists.lagda.md | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/plfa/part1/Lists.lagda.md b/src/plfa/part1/Lists.lagda.md
index de388e4f..0b013423 100644
--- a/src/plfa/part1/Lists.lagda.md
+++ b/src/plfa/part1/Lists.lagda.md
@@ -1031,7 +1031,7 @@ decidable, using `_∷_` rather than `⟨_,_⟩` to combine the evidence for
the head and tail of the list.
-#### Exercise `any?` (stretch)
+#### Exercise `Any?` (stretch)
Just as `All` has analogues `all` and `All?` which determine whether a
predicate holds for every element of a list, so does `Any` have
From 6f1933c141f4b5a9bbbaaa30c359324d3f30bd79 Mon Sep 17 00:00:00 2001
From: wadler <wadler@inf.ed.ac.uk>
Date: Mon, 28 Oct 2019 11:14:22 +0000
Subject: [PATCH 5/9] minor fix to Inference
---
src/plfa/part2/Inference.lagda.md | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/src/plfa/part2/Inference.lagda.md b/src/plfa/part2/Inference.lagda.md
index aabd52ff..cd89e5c4 100644
--- a/src/plfa/part2/Inference.lagda.md
+++ b/src/plfa/part2/Inference.lagda.md
@@ -584,7 +584,7 @@ ext∋ : ∀ {Γ B x y}
-----------------------------
→ ¬ ∃[ A ]( Γ , y ⦂ B ∋ x ⦂ A )
ext∋ x≢y _ ⟨ A , Z ⟩ = x≢y refl
-ext∋ _ ¬∃ ⟨ A , S _ ⊢x ⟩ = ¬∃ ⟨ A , ⊢x ⟩
+ext∋ _ ¬∃ ⟨ A , S _ ∋x ⟩ = ¬∃ ⟨ A , ∋x ⟩
```
Given a type `A` and evidence that `Γ , y ⦂ B ∋ x ⦂ A` holds, we must
demonstrate a contradiction. If the judgment holds by `Z`, then we
@@ -604,7 +604,7 @@ lookup (Γ , y ⦂ B) x with x ≟ y
... | yes refl = yes ⟨ B , Z ⟩
... | no x≢y with lookup Γ x
... | no ¬∃ = no (ext∋ x≢y ¬∃)
-... | yes ⟨ A , ⊢x ⟩ = yes ⟨ A , S x≢y ⊢x ⟩
+... | yes ⟨ A , ∋x ⟩ = yes ⟨ A , S x≢y ∋x ⟩
```
Consider the context:
@@ -1027,7 +1027,7 @@ Next, we give the code to erase a lookup judgment:
```
∥_∥∋ : ∀ {Γ x A} → Γ ∋ x ⦂ A → ∥ Γ ∥Cx DB.∋ ∥ A ∥Tp
∥ Z ∥∋ = DB.Z
-∥ S x≢ ⊢x ∥∋ = DB.S ∥ ⊢x ∥∋
+∥ S x≢ ∋x ∥∋ = DB.S ∥ ∋x ∥∋
```
It simply drops the evidence that variable names are distinct.
From d2ff9564ce40193413d677cc5de7cf814f066067 Mon Sep 17 00:00:00 2001
From: wadler <wadler@inf.ed.ac.uk>
Date: Mon, 28 Oct 2019 11:26:49 +0000
Subject: [PATCH 6/9] added midterm survey
---
courses/tspl/2019/tspl2019.md | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/courses/tspl/2019/tspl2019.md b/courses/tspl/2019/tspl2019.md
index 07471588..911c430b 100644
--- a/courses/tspl/2019/tspl2019.md
+++ b/courses/tspl/2019/tspl2019.md
@@ -144,6 +144,12 @@ but talk to me if you want to formalise something else.
* Optional project cw6 due 4pm Thursday 28 November (Week 11)
+## Midterm course feedback
+
+You may offer feedback on the course at
+[https://www.surveymonkey.co.uk/r/YX7ZFYC](https://www.surveymonkey.co.uk/r/YX7ZFYC).
+Please do so by 4pm Thursday 31 October.
+
<!--
From 749e6a9e57e1ecfa5ebb0909043d7fc8f6ce98cd Mon Sep 17 00:00:00 2001
From: wadler <wadler@inf.ed.ac.uk>
Date: Mon, 28 Oct 2019 12:00:38 +0000
Subject: [PATCH 7/9] renamed exercises
---
courses/tspl/2019/tspl2019.md | 1 +
src/plfa/part2/Lambda.lagda.md | 4 ++--
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/courses/tspl/2019/tspl2019.md b/courses/tspl/2019/tspl2019.md
index 911c430b..598bd318 100644
--- a/courses/tspl/2019/tspl2019.md
+++ b/courses/tspl/2019/tspl2019.md
@@ -148,6 +148,7 @@ but talk to me if you want to formalise something else.
You may offer feedback on the course at
[https://www.surveymonkey.co.uk/r/YX7ZFYC](https://www.surveymonkey.co.uk/r/YX7ZFYC).
+
Please do so by 4pm Thursday 31 October.
diff --git a/src/plfa/part2/Lambda.lagda.md b/src/plfa/part2/Lambda.lagda.md
index 95ffff8a..bd190f55 100644
--- a/src/plfa/part2/Lambda.lagda.md
+++ b/src/plfa/part2/Lambda.lagda.md
@@ -1359,7 +1359,7 @@ or explain why there are no such types.
2. `` ∅ , "x" ⦂ A , "y" ⦂ B ⊢ ƛ "z" ⇒ ` "x" · (` "y" · ` "z") ⦂ C ``
-#### Exercise `mul-type` (recommended)
+#### Exercise `⊢mul` (recommended)
Using the term `mul` you defined earlier, write out the derivation
showing that it is well typed.
@@ -1369,7 +1369,7 @@ showing that it is well typed.
```
-#### Exercise `mulᶜ-type` (practice)
+#### Exercise `⊢mulᶜ` (practice)
Using the term `mulᶜ` you defined earlier, write out the derivation
showing that it is well typed.
From 9f0ae6e4b6ee8226191a1e3ea455883030f931d9 Mon Sep 17 00:00:00 2001
From: wadler <wadler@inf.ed.ac.uk>
Date: Mon, 28 Oct 2019 15:19:47 +0000
Subject: [PATCH 8/9] fixed exercise in List
---
src/plfa/part1/Lists.lagda.md | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/src/plfa/part1/Lists.lagda.md b/src/plfa/part1/Lists.lagda.md
index 0b013423..1f0020d1 100644
--- a/src/plfa/part1/Lists.lagda.md
+++ b/src/plfa/part1/Lists.lagda.md
@@ -958,11 +958,11 @@ Show that the equivalence `All-++-⇔` can be extended to an isomorphism.
-- Your code goes here
```
-#### Exercise `¬Any≃All¬` (recommended)
+#### Exercise `¬Any⇔All¬` (recommended)
Show that `Any` and `All` satisfy a version of De Morgan's Law:
- (¬_ ∘ Any P) xs ≃ All (¬_ ∘ P) xs
+ (¬_ ∘ Any P) xs ⇔ All (¬_ ∘ P) xs
(Can you see why it is important that here `_∘_` is generalised
to arbitrary levels, as described in the section on
@@ -970,11 +970,24 @@ to arbitrary levels, as described in the section on
Do we also have the following?
- (¬_ ∘ All P) xs ≃ Any (¬_ ∘ P) xs
+ (¬_ ∘ All P) xs ⇔ Any (¬_ ∘ P) xs
If so, prove; if not, explain why.
+```
+-- Your code goes here
+```
+
+#### Exercise `¬Any≃All¬` (stretch)
+
+Show that the equivalence `¬Any⇔All¬` can be extended to an isomorphism.
+You will need to use extensionality.
+
+```
+-- Your code goes here
+```
+
#### Exercise `All-∀` (practice)
Show that `All P xs` is isomorphic to `∀ {x} → x ∈ xs → P x`.
From c0d9e7851e7a1e17a40811366cc5c74b7ac5f40e Mon Sep 17 00:00:00 2001
From: wadler <wadler@inf.ed.ac.uk>
Date: Mon, 28 Oct 2019 16:29:01 +0000
Subject: [PATCH 9/9] Updated exercise in Lists and Assignment3
---
courses/tspl/2019/Assignment3.lagda.md | 23 ++++++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)
diff --git a/courses/tspl/2019/Assignment3.lagda.md b/courses/tspl/2019/Assignment3.lagda.md
index c1782e0b..5e00b72d 100644
--- a/courses/tspl/2019/Assignment3.lagda.md
+++ b/courses/tspl/2019/Assignment3.lagda.md
@@ -220,6 +220,7 @@ replacement for `_×_`. As a consequence, demonstrate an equivalence relating
-- Your code goes here
```
+
#### Exercise `All-++-≃` (stretch)
Show that the equivalence `All-++-⇔` can be extended to an isomorphism.
@@ -228,11 +229,12 @@ Show that the equivalence `All-++-⇔` can be extended to an isomorphism.
-- Your code goes here
```
-#### Exercise `¬Any≃All¬` (recommended)
+
+#### Exercise `¬Any⇔All¬` (recommended)
Show that `Any` and `All` satisfy a version of De Morgan's Law:
- (¬_ ∘ Any P) xs ≃ All (¬_ ∘ P) xs
+ (¬_ ∘ Any P) xs ⇔ All (¬_ ∘ P) xs
(Can you see why it is important that here `_∘_` is generalised
to arbitrary levels, as described in the section on
@@ -240,11 +242,26 @@ to arbitrary levels, as described in the section on
Do we also have the following?
- (¬_ ∘ All P) xs ≃ Any (¬_ ∘ P) xs
+ (¬_ ∘ All P) xs ⇔ Any (¬_ ∘ P) xs
If so, prove; if not, explain why.
+```
+-- Your code goes here
+```
+
+
+#### Exercise `¬Any≃All¬` (stretch)
+
+Show that the equivalence `¬Any⇔All¬` can be extended to an isomorphism.
+You will need to use extensionality.
+
+```
+-- Your code goes here
+```
+
+
#### Exercise `All-∀` (practice)
Show that `All P xs` is isomorphic to `∀ {x} → x ∈ xs → P x`.