diff --git a/notes/.obsidian/plugins/obsidian-to-anki-plugin/data.json b/notes/.obsidian/plugins/obsidian-to-anki-plugin/data.json
index 4d8ffaa..7ed6084 100644
--- a/notes/.obsidian/plugins/obsidian-to-anki-plugin/data.json
+++ b/notes/.obsidian/plugins/obsidian-to-anki-plugin/data.json
@@ -620,7 +620,7 @@
     "_journal/2024-07/2024-07-18.md": "237918b58424435959cbc949d01e7932",
     "_journal/2024-07-20.md": "d8685729effc374e4ece1e618c2fdad3",
     "_journal/2024-07/2024-07-19.md": "e9fe4569f88e1ba9393292bcf092edfc",
-    "_journal/2024-07-21.md": "682ee0ada782dd281d8fd217227e985c",
+    "_journal/2024-07-21.md": "dd5dd93f119f69571a78e027fab7da5d",
     "_journal/2024-07/2024-07-20.md": "d8685729effc374e4ece1e618c2fdad3",
     "logic/classical/index.md": "ee0a4b2bfcfa2cab0880db449cb62df1",
     "logic/classical/truth-tables.md": "b739e2824a4a5c26ac446e7c15ce02aa",
@@ -630,7 +630,8 @@
     "formal-system/logical-system/pred-logic.md": "2524ccc09561bc219dab3f32010a0161",
     "formal-system/logical-system/prop-logic.md": "b61ce051795d5a951c763b928ec5cea8",
     "formal-system/index.md": "3d31c99bffdcb05de9f2e32ac6319952",
-    "programming/short-circuit.md": "c256ced42dc3b493aff5a356e5383b6e"
+    "programming/short-circuit.md": "c256ced42dc3b493aff5a356e5383b6e",
+    "formal-system/abstract-rewriting.md": "8424314a627851c5b94be6163f64ba30"
   },
   "fields_dict": {
     "Basic": [
diff --git a/notes/abstract-rewriting-systems/normal-form.md b/notes/abstract-rewriting-systems/normal-form.md
deleted file mode 100644
index 225706f..0000000
--- a/notes/abstract-rewriting-systems/normal-form.md
+++ /dev/null
@@ -1,44 +0,0 @@
----
-title: Normal Form
-TARGET DECK: Obsidian::STEM
-FILE TAGS: ars::normal
-tags:
-  - ars
----
-
-## Overview
-
-An object is said to be in **normal form** if it cannot be reduced any further. Examples of normal form include:
-
-* [[truth-tables|Conjunctive Normal Form]]
-* [[truth-tables|Disjunctive Normal Form]]
-* [[pred-logic#Identifiers|Prenex Normal Form]]
-* [[beta-reduction#Normal Form|β-normal forms]]
-
-%%ANKI
-Basic
-What does it mean for an object to be in normal form?
-Back: It cannot be rewritten/reduced any further.
-Reference: Gries, David. *The Science of Programming*. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
-<!--ID: 1707675146194-->
-END%%
-
-%%ANKI
-Basic
-What zero-order logical normal form(s) have only $\land$ and $\lor$ operators?
-Back: CNF and DNF.
-Reference: Gries, David. *The Science of Programming*. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
-<!--ID: 1707675369145-->
-END%%
-
-%%ANKI
-Basic
-What first-order logical normal form(s) writes bound identifiers before free ones?
-Back: PNF
-Reference: Gries, David. *The Science of Programming*. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
-<!--ID: 1707675369187-->
-END%%
-
-## Bibliography
-
-* Gries, David. *The Science of Programming*. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
\ No newline at end of file
diff --git a/notes/abstract-rewriting-systems/index.md b/notes/formal-system/abstract-rewriting.md
similarity index 80%
rename from notes/abstract-rewriting-systems/index.md
rename to notes/formal-system/abstract-rewriting.md
index aff4701..21c923e 100644
--- a/notes/abstract-rewriting-systems/index.md
+++ b/notes/formal-system/abstract-rewriting.md
@@ -1,15 +1,23 @@
 ---
 title: Abstract Rewriting Systems
 TARGET DECK: Obsidian::STEM
-FILE TAGS: ars
+FILE TAGS: formal-system::abstract-rewriting
 tags:
-  - ars
+  - abstract-rewriting
+  - formal-system
 ---
 
 ## Overview
 
 In an **abstract rewriting system** (ARS), an object is said to be in **normal form** if it cannot be rewritten any further, i.e. it is irreducible. An object is said to be in **canonical form** if it is presented in the "standard" representation (where "standard" is defined per field).
 
+Examples of normal form include:
+
+* [[truth-tables|Conjunctive Normal Form]]
+* [[truth-tables|Disjunctive Normal Form]]
+* [[pred-logic#Identifiers|Prenex Normal Form]]
+* [[beta-reduction#Normal Form|β-normal forms]]
+
 In most fields, a canoncial form specifies a *unique* representation.
 
 %%ANKI
@@ -59,6 +67,30 @@ Reference: “Canonical Form,” in _Wikipedia_, January 7, 2024, [https://en.wi
 <!--ID: 1719067812833-->
 END%%
 
+%%ANKI
+Basic
+What does it mean for an object to be in normal form?
+Back: It cannot be rewritten/reduced any further.
+Reference: Gries, David. *The Science of Programming*. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
+<!--ID: 1707675146194-->
+END%%
+
+%%ANKI
+Basic
+What zero-order logical normal form(s) have only $\land$ and $\lor$ operators?
+Back: CNF and DNF.
+Reference: Gries, David. *The Science of Programming*. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
+<!--ID: 1707675369145-->
+END%%
+
+%%ANKI
+Basic
+What first-order logical normal form(s) writes bound identifiers before free ones?
+Back: PNF
+Reference: Gries, David. *The Science of Programming*. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
+<!--ID: 1707675369187-->
+END%%
+
 ## Confluence
 
 **Confluence** is the property by which two different terms can be further reduced to one common term. That is to say, confluence is a property of rewriting systems describing which terms in such a system can be rewritten in more than one way.