`. What term is used to refer to ``?
+Back: The prefix.
+Reference: “XML Namespace,” in _Wikipedia_, April 11, 2024, [https://en.wikipedia.org/w/index.php?title=XML_namespace](https://en.wikipedia.org/w/index.php?title=XML_namespace&oldid=1218316095).
+
+END%%
+
+%%ANKI
+Basic
+Consider `xmlns:
=`. What term is used to refer to ``?
+Back: The namespace name.
+Reference: “XML Namespace,” in _Wikipedia_, April 11, 2024, [https://en.wikipedia.org/w/index.php?title=XML_namespace](https://en.wikipedia.org/w/index.php?title=XML_namespace&oldid=1218316095).
+
+END%%
+
+%%ANKI
+Basic
+What namespace name is used in the following XML attribute?
+```xml
+<... xmlns:xhtml="http://www.w3.org/1999/xhtml">
+```
+Back: `http://www.w3.org/1999/xhtml`
+Reference: “XML Namespace,” in _Wikipedia_, April 11, 2024, [https://en.wikipedia.org/w/index.php?title=XML_namespace](https://en.wikipedia.org/w/index.php?title=XML_namespace&oldid=1218316095).
+
+END%%
+
+%%ANKI
+Basic
+What prefix is used in the following XML attribute?
+```xml
+<... xmlns:xhtml="http://www.w3.org/1999/xhtml">
+```
+Back: `xhtml`
+Reference: “XML Namespace,” in _Wikipedia_, April 11, 2024, [https://en.wikipedia.org/w/index.php?title=XML_namespace](https://en.wikipedia.org/w/index.php?title=XML_namespace&oldid=1218316095).
+
+END%%
+
+%%ANKI
+Basic
+What does it mean to use an `xmlns` attribute without a prefix?
+Back: This declares the default namespace of the associated tag.
+Reference: “XML Namespace,” in _Wikipedia_, April 11, 2024, [https://en.wikipedia.org/w/index.php?title=XML_namespace](https://en.wikipedia.org/w/index.php?title=XML_namespace&oldid=1218316095).
+
+END%%
+
+%%ANKI
+Basic
+What does it mean to use an `xmlns` attribute without a namespace name?
+Back: N/A. This is invalid syntax.
+Reference: “XML Namespace,” in _Wikipedia_, April 11, 2024, [https://en.wikipedia.org/w/index.php?title=XML_namespace](https://en.wikipedia.org/w/index.php?title=XML_namespace&oldid=1218316095).
+
+END%%
+
+%%ANKI
+Basic
+How do I declare a new XML namespace with prefix `abc`?
+Back: By including `xmlns:abc=` in the appropriate tag.
+Reference: “XML Namespace,” in _Wikipedia_, April 11, 2024, [https://en.wikipedia.org/w/index.php?title=XML_namespace](https://en.wikipedia.org/w/index.php?title=XML_namespace&oldid=1218316095).
+
+END%%
+
+%%ANKI
+Basic
+Suppose there is no default namespace in scope. What namespace are elements assigned?
+Back: N/A. They are not considered members of any namespace.
+Reference: “XML Namespace,” in _Wikipedia_, April 11, 2024, [https://en.wikipedia.org/w/index.php?title=XML_namespace](https://en.wikipedia.org/w/index.php?title=XML_namespace&oldid=1218316095).
+
+END%%
+
+%%ANKI
+Basic
+Which namespace is `bar` a member of?
+```xml
+
+
+
+```
+Back: `ns2`
+Reference: “XML Namespace,” in _Wikipedia_, April 11, 2024, [https://en.wikipedia.org/w/index.php?title=XML_namespace](https://en.wikipedia.org/w/index.php?title=XML_namespace&oldid=1218316095).
+
+END%%
+
+%%ANKI
+Basic
+Which namespace is `bar` a member of?
+```xml
+
+
+
+```
+Back: `ns1`
+Reference: “XML Namespace,” in _Wikipedia_, April 11, 2024, [https://en.wikipedia.org/w/index.php?title=XML_namespace](https://en.wikipedia.org/w/index.php?title=XML_namespace&oldid=1218316095).
+
+END%%
+
+%%ANKI
+Basic
+Which namespace is attribute `a` a member of?
+```xml
+
+
+
+```
+Back: N/A. `a` has no namespace.
+Reference: “XML Namespace,” in _Wikipedia_, April 11, 2024, [https://en.wikipedia.org/w/index.php?title=XML_namespace](https://en.wikipedia.org/w/index.php?title=XML_namespace&oldid=1218316095).
+
+END%%
+
+%%ANKI
+Basic
+Which namespace is attribute `b` a member of?
+```xml
+
+
+
+```
+Back: N/A. `b` has no namespace.
+Reference: “XML Namespace,” in _Wikipedia_, April 11, 2024, [https://en.wikipedia.org/w/index.php?title=XML_namespace](https://en.wikipedia.org/w/index.php?title=XML_namespace&oldid=1218316095).
+
+END%%
+
+%%ANKI
+Basic
+Which namespace is attribute `b` a member of?
+```xml
+
+
+
+```
+Back: `p`
+Reference: “XML Namespace,” in _Wikipedia_, April 11, 2024, [https://en.wikipedia.org/w/index.php?title=XML_namespace](https://en.wikipedia.org/w/index.php?title=XML_namespace&oldid=1218316095).
+
+END%%
+
+## Bibliography
+
+* Allemang, Dean, James A. Hendler, and Fabien L. Gandon. _Semantic Web for the Working Ontologist_. 3e ed. ACM Books 33. New York: Association for computing machinery, 2020.
+* “XML,” in _Wikipedia_, November 2, 2024, [https://en.wikipedia.org/w/index.php?title=XML](https://en.wikipedia.org/w/index.php?title=XML&oldid=1254990843).
+* “XML Namespace,” in _Wikipedia_, April 11, 2024, [https://en.wikipedia.org/w/index.php?title=XML_namespace](https://en.wikipedia.org/w/index.php?title=XML_namespace&oldid=1218316095).
\ No newline at end of file
diff --git a/notes/posix/signals.md b/notes/posix/signals.md
index d4cbdf5..7f4fb67 100644
--- a/notes/posix/signals.md
+++ b/notes/posix/signals.md
@@ -9,8 +9,6 @@ tags:
## Overview
-This is an overview of specific POSIX signals.
-
Code | Name
----- | --------------
1 | SIGHUP
@@ -24,8 +22,6 @@ Code | Name
13 | SIGPIPE
15 | SIGTERM
-## Details
-
%%ANKI
Basic
What command can we run to access the official manual page for signals?
@@ -50,7 +46,15 @@ Reference: Cooper, Mendel. “Advanced Bash-Scripting Guide,” n.d., 916.
END%%
-### SIGHUP (1)
+%%ANKI
+Basic
+What does it mean for a program to (perform a) trap?
+Back: It is terminated abruptly before its usual end.
+Reference: Jens Gustedt, _Modern C_ (Shelter Island, NY: Manning Publications Co, 2020).
+
+END%%
+
+## SIGHUP (1)
A process receives a `SIGHUP` signal when the terminal it is attached to goes away before it finishes executing.
@@ -129,7 +133,7 @@ Reference: `man 1 ps`
END%%
-### SIGINT (2)
+## SIGINT (2)
Indicates the process was interrupted by the user. Happens when pressing `Ctrl-C` from the controlling terminal.
@@ -156,7 +160,7 @@ Reference: Dowling, “A List of Signals and What They Mean.”
END%%
-### SIGILL (4)
+## SIGILL (4)
Indicates the CPU encountered an instruction it does not understand or does not have permission to execute. Can often indicate corruption in some way or perhaps an attempt to execute data instead of code.
@@ -199,7 +203,7 @@ Reference: Dowling, “A List of Signals and What They Mean.”
END%%
-### SIGABRT (6)
+## SIGABRT (6)
A signal, usually sent when the process itself invokes `abort()`. Indicates an "emergency stop".
@@ -221,7 +225,7 @@ END%%
%%ANKI
Basic
-What signal corresponds to the idea of an "emergency stop"?
+Which signal corresponds to the idea of an "emergency stop"?
Back: `SIGABRT`
Reference: Dowling, “A List of Signals and What They Mean.”
@@ -245,12 +249,39 @@ Tags: c17
END%%
+## SIGBUS (7)
+
+Indicates the CPU encountered an instruction to access memory it cannot physically address, i.e. an invalid address for the address bus.
+
+%%ANKI
+Cloze
+Signal {`SIGBUS`} corresponds to number {7}.
+Reference: Dowling, “A List of Signals and What They Mean.”
+
+END%%
+
%%ANKI
Basic
-What does it mean for a program to (perform a) trap?
-Back: It is terminated abruptly before its usual end.
-Reference: Jens Gustedt, _Modern C_ (Shelter Island, NY: Manning Publications Co, 2020).
-
+Which signal usually corresponds to alignment errors when accessing memory?
+Back: `SIGBUS`
+Reference: Dowling, “A List of Signals and What They Mean.”
+
+END%%
+
+%%ANKI
+Basic
+When does the CPU emit a `SIGBUS` signal?
+Back: When it tries accessing memory it cannot physically address.
+Reference: Dowling, “A List of Signals and What They Mean.”
+
+END%%
+
+%%ANKI
+Basic
+What is the `BUS` in `SIGBUS` short for?
+Back: **Bus** error.
+Reference: Dowling, “A List of Signals and What They Mean.”
+
END%%
## Bibliography
diff --git a/notes/set/cardinality.md b/notes/set/cardinality.md
index c24554f..8c19af6 100644
--- a/notes/set/cardinality.md
+++ b/notes/set/cardinality.md
@@ -36,7 +36,7 @@ END%%
%%ANKI
Basic
-Suppose there exists a one-to-one function $F$ from $A$ into $B$. When is $A \approx B$?
+Suppose there exists a one-to-one function $F$ from $A$ into $B$. When does this imply $A \approx B$?
Back: When $F$ is also onto $B$.
Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
@@ -44,7 +44,7 @@ END%%
%%ANKI
Basic
-Suppose there exists a function $F$ from $A$ onto $B$. When is $A \approx B$?
+Suppose there exists a function $F$ from $A$ onto $B$. When does this imply $A \approx B$?
Back: When $F$ is also one-to-one.
Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
@@ -52,7 +52,7 @@ END%%
%%ANKI
Basic
-Suppose there exists a one-to-one function $F$ from $A$ onto $B$. When is $A \approx B$?
+Suppose there exists a one-to-one function $F$ from $A$ onto $B$. When does this imply $A \approx B$?
Back: Always, by definition.
Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
@@ -435,6 +435,321 @@ Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Pre
END%%
+If one set $A$ of cardinality $\kappa$ is finite, then all of them are. In this case $\kappa$ is a **finite cardinal**. Otherwise $\kappa$ is an **infinite cardinal**.
+
+%%ANKI
+Basic
+How many sets $A$ exist such that $\mathop{\text{card}} A = 0$?
+Back: $1$
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+How many sets $A$ exist such that $\mathop{\text{card}} A = n^+$ for some $n \in \omega$?
+Back: An infinite many.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $n \in \omega$. When is $\{X \mid \mathop{\text{card}} X = n\}$ a set?
+Back: When $n = 0$.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $n \in \omega$. When is $\{X \mid \mathop{\text{card}} X = n\}$ a class?
+Back: Always.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+What class can we construct to prove $\{X \mid \mathop{\text{card}} X = 1\}$ is not a set?
+Back: $\bigcup\, \{\{X\} \mid X \text{ is a set} \}$, i.e. the union of all singleton sets.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+What is a finite cardinal?
+Back: A cardinal number equal to $\mathop{\text{card}} A$ for some finite set $A$.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+What is an infinite cardinal?
+Back: A cardinal number equal to $\mathop{\text{card}} A$ for some infinite set $A$.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+The finite cardinals are exactly what more basic set?
+Back: $\omega$
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+What set does $\aleph_0$ refer to?
+Back: $\mathop{\text{card}} \omega$
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+What is the "smallest" infinite cardinal?
+Back: $\aleph_0$
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $C \subseteq A$ where $A \approx n$ for some $n \in \omega$. What does $\mathop{\text{card}} C$ evaluate to?
+Back: A natural number $m$ such that $m \underline{\in} n$.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $C \subset A$ where $A \approx n$ for some $n \in \omega$. What does $\mathop{\text{card}} C$ evaluate to?
+Back: A natural number $m$ such that $m \in n$.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+How is proposition "any subset of a finite set is finite" expressed in FOL?
+Back: $\forall n \in \omega, \forall A \approx n, \forall B \subseteq A, \exists m \in n, B \approx m$
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+How is the following more succinctly stated? $$\forall n \in \omega, \forall A \approx n, \forall B \subseteq A, \exists m \in n, B \approx m$$
+Back: Any subset of a finite set is finite.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Suppose sets $A$ and $B$ are finite. When is $A \cup B$ infinite?
+Back: The union of two finite sets is always finite.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $m, n \in \omega$ s.t. $A \approx m$ and $B \approx n$. What is the largest value $\mathop{\text{card}}(A \cup B)$ can evaluate to?
+Back: $m + n$
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $m, n \in \omega$ s.t. $A \approx m$ and $B \approx n$. What is the smallest value $\mathop{\text{card}}(A \cup B)$ can evaluate to?
+Back: $\mathop{\text{max}}(m, n)$
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $m, n \in \omega$ s.t. $A \approx m$ and $B \approx n$. When does $\mathop{\text{card}}(A \cup B) = m + n$?
+Back: When $A$ and $B$ are disjoint.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $m, n \in \omega$ s.t. $A \approx m$ and $B \approx n$. When does $\mathop{\text{card}}(A \cup B) = m$?
+Back: When $B \subseteq A$.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Suppose sets $A$ and $B$ are finite. When is $A \cap B$ finite?
+Back: The intersection of two finite sets is always finite.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $m, n \in \omega$ s.t. $A \approx m$ and $B \approx n$. What is the largest value $\mathop{\text{card}}(A \cap B)$ can evaluate to?
+Back: $\mathop{\text{min}}(m, n)$
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $m, n \in \omega$ s.t. $A \approx m$ and $B \approx n$. What is the smallest value $\mathop{\text{card}}(A \cap B)$ can evaluate to?
+Back: $0$
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Suppose sets $A$ and $B$ are finite. When is $A \times B$ finite?
+Back: The Cartesian product of two finite sets is always finite.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $m, n \in \omega$ such that $A \approx m$ and $B \approx n$. What does $\mathop{\text{card}}(A \times B)$ evaluate to?
+Back: $m \cdot n$
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+### Addition
+
+Let $\kappa$ and $\lambda$ be any cardinal numbers. Then $\kappa + \lambda = \mathop{\text{card}}(K \cup L)$, where $K$ and $L$ are any disjoint sets of cardinality $\kappa$ and $\lambda$, respectively.
+
+%%ANKI
+Basic
+Let $\kappa$ and $\lambda$ be any cardinal numbers. How is $\kappa + \lambda$ defined?
+Back: As $\mathop{\text{card}}(K \cup L)$ where $K$ and $L$ are disjoint sets with cardinality $\kappa$ and $\lambda$, respectively.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $K$ and $L$ be sets. How is $\mathop{\text{card}}(K \cup L)$ expressed in terms of cardinal numbers?
+Back: N/A. $K$ and $L$ must be *disjoint* sets for this to make sense.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $K$ and $L$ be disjoint sets. How is $\mathop{\text{card}}(K \cup L)$ expressed in terms of cardinal numbers?
+Back: As $\kappa + \lambda$ where $\kappa = \mathop{\text{card}} K$ and $\lambda = \mathop{\text{card}} L$.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $K \approx \kappa$ and $L \approx \lambda$. What is necessary for $\mathop{\text{card}}(K \cup L) \approx \kappa + \lambda$?
+Back: That $K$ and $L$ are disjoint.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Cloze
+{Addition} of cardinal numbers is defined in terms of the {union} of sets.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+### Multiplication
+
+Let $\kappa$ and $\lambda$ be any cardinal numbers. Then $\kappa \cdot \lambda = \mathop{\text{card}}(K \times L)$, where $K$ and $L$ are any sets of cardinality $\kappa$ and $\lambda$, respectively.
+
+%%ANKI
+Basic
+Let $\kappa$ and $\lambda$ be any cardinal numbers. How is $\kappa \cdot \lambda$ defined?
+Back: As $\mathop{\text{card}}(K \times L)$ where $K$ and $L$ are sets with cardinality $\kappa$ and $\lambda$, respectively.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $K$ and $L$ be sets. How is $\mathop{\text{card}}(K \times L)$ expressed in terms of cardinal numbers?
+Back: As $\kappa \cdot \lambda$ where $\kappa = \mathop{\text{card}} K$ and $\lambda = \mathop{\text{card}} L$.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $K \approx \kappa$ and $L \approx \lambda$. What is necessary for $\mathop{\text{card}}(K \times L) \approx \kappa \cdot \lambda$?
+Back: N/A. This is true by definition.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Cloze
+{Multiplication} of cardinal numbers is defined in terms of the {Cartesian product} of sets.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+### Exponentiation
+
+Let $\kappa$ and $\lambda$ be any cardinal numbers. Then $\kappa^\lambda = \mathop{\text{card}}(^LK)$, where $K$ and $L$ are any sets of cardinality $\kappa$ and $\lambda$, respectively.
+
+%%ANKI
+Basic
+Let $\kappa$ and $\lambda$ be any cardinal numbers. How is $\kappa^\lambda$ defined?
+Back: As $\mathop{\text{card}}(^LK)$ where $K$ and $L$ are sets with cardinality $\kappa$ and $\lambda$, respectively.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $K$ and $L$ be sets. How is $\mathop{\text{card}}(^LK)$ expressed in terms of cardinal numbers?
+Back: As $\kappa^\lambda$ where $\kappa = \mathop{\text{card}} K$ and $\lambda = \mathop{\text{card}} L$.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $K$ and $L$ be sets. How is $\mathop{\text{card}}(^KL)$ expressed in terms of cardinal numbers?
+Back: As $\lambda^\kappa$ where $\kappa = \mathop{\text{card}} K$ and $\lambda = \mathop{\text{card}} L$.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Basic
+Let $K \approx \kappa$ and $L \approx \lambda$. What is necessary for $\mathop{\text{card}}(^LK) \approx \kappa^\lambda$?
+Back: N/A. This is true by definition.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
+%%ANKI
+Cloze
+{Exponentiation} of cardinal numbers is defined in terms of the {set of functions} between sets.
+Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
+
+END%%
+
## Bibliography
* Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
\ No newline at end of file
diff --git a/notes/set/graphs.md b/notes/set/graphs.md
index f8e9f82..db18776 100644
--- a/notes/set/graphs.md
+++ b/notes/set/graphs.md
@@ -1064,7 +1064,7 @@ END%%
%%ANKI
Basic
In an undirected graph, when is $\langle v_0, v_1, \ldots, v_k \rangle$ considered a non-trivial cycle?
-Back: When $v_0 = v_k$, $k > 0$, and all edges in the path are distinct.
+Back: When the tuple forms a path satisfying $v_0 = v_k$ for some $k > 0$.
Reference: Thomas H. Cormen et al., Introduction to Algorithms, Fourth edition (Cambridge, Massachusett: The MIT Press, 2022).
END%%
diff --git a/notes/set/relations.md b/notes/set/relations.md
index c69dc69..e73567a 100644
--- a/notes/set/relations.md
+++ b/notes/set/relations.md
@@ -1259,7 +1259,7 @@ END%%
%%ANKI
Basic
Can a relation be both reflexive and trichotomous?
-Back: Yes.
+Back: Yes, the empty relation.
Reference: Herbert B. Enderton, *Elements of Set Theory* (New York: Academic Press, 1977).
END%%
diff --git a/notes/x86-64/instructions/conditions.md b/notes/x86-64/instructions/conditions.md
index ce6f41f..ce67e7f 100644
--- a/notes/x86-64/instructions/conditions.md
+++ b/notes/x86-64/instructions/conditions.md
@@ -745,7 +745,7 @@ END%%
%%ANKI
Basic
-Is the following considered a direct or indirect jump?
+Is the following considered a direct or indirect jump instruction?
```x86
jmp *(%rax)
```
@@ -756,7 +756,7 @@ END%%
%%ANKI
Basic
-Is the following considered a direct or indirect jump?
+Is the following considered a direct or indirect jump instruction?
```x86
jmp .L1
```
@@ -767,7 +767,7 @@ END%%
%%ANKI
Basic
-Is the following considered a direct or indirect jump?
+Is the following considered a direct or indirect jump instruction?
```x86
jmp *%rax
```
@@ -778,7 +778,7 @@ END%%
%%ANKI
Basic
-Is the following considered a direct or indirect jump?
+Is the following considered a direct or indirect jump instruction?
```x86
jg *%rax
```
diff --git a/notes/x86-64/procedures.md b/notes/x86-64/procedures.md
index 902480b..3265e0b 100644
--- a/notes/x86-64/procedures.md
+++ b/notes/x86-64/procedures.md
@@ -37,7 +37,7 @@ END%%
%%ANKI
Basic
-What instructions are used to store and retrieve from the x86-64 stack?
+What two instructions are used to adjust the top of the x86-64 stack?
Back: `pushq` and `popq`.
Reference: Bryant, Randal E., and David O'Hallaron. *Computer Systems: A Programmer's Perspective*. Third edition, Global edition. Always Learning. Pearson, 2016.