housekeeping

zk/Assembly.md

@@ -4,8 +4,6 @@ tags: [CPU]
 created: Tuesday, March 12, 2024
 ---
 
-# Assembly
-
 - Assembly is one level up from machine code and provides a more human-friendly
   abstraction layer
 
@@ -38,8 +36,3 @@ A disassembler does the opposite: translate machine code into assembly.
   directly executed by the CPU
 - humans use an assembly language version of the machine code which is then
   translated back to machine code for the computer to execute.
-
-## Related notes
-
-[[Hexadecimal_number_system]], [[Instruction_set_architectures]],
-[[CPU_architecture]]

zk/Attributes_of_Internet_enclosure.md

@@ -3,8 +3,6 @@ tags: [ecopolsoc, internet]
 created: Friday, November 22, 2024
 ---
 
-# a771a6d9_defining_internet_enclosure
-
 ## Defining _enclosure_
 
 The attempt by capital interests to encircle, control and contain networked

zk/Biconditional_Introduction.md

@@ -3,8 +3,6 @@ tags:
   - logic
 ---
 
-# Biconditional introduction
-
 The biconditional means if $P$ is the case, $Q$ must be the case and if $Q$ is
 the case, $P$ must be the case. Thus to introduce this operator we must
 demonstrate both that $Q$ follows from $P$ and that $P$ follows from $Q$. We do

zk/Bitwise_operators.md

@@ -4,8 +4,6 @@ tags: [binary]
 created: Saturday, April 20, 2024
 ---
 
-# Bitwise operators
-
 In addition to mathematical, logical and comparison operators, there are
 _bitwise operators_. These operators execute conditions based on the actual bits
 of a value rather than the values that the bits are encoded to represent.
@@ -68,5 +66,3 @@ operations are the fastest and lowest level of computation, being able to
 directly access and operate on bits within a programming language can be
 beneficial when efficiency and speed of execution is a factor or when memory is
 constrained.
-
-## Related notes

zk/Boolean_function_synthesis.md

@@ -5,21 +5,16 @@ tags:
   - logic
 ---
 
-# Boolean function synthesis
+When we looked at [boolean functions](Boolean_functions.md) we were working in a
-
+particular direction: from a function to a truth table. When we do Boolean
-When we looked at
+function synthesis we work in the opposite direction: from a truth table to a
-[boolean functions](Boolean_functions.md) we were
+function.
-working in a particular direction: from a function to a truth table. When we do
-Boolean function synthesis we work in the opposite direction: from a truth table
-to a function.
 
 This is an important skill that we will use when constructing
-[logic circuits](Digital_circuits.md).
+[logic circuits](Digital_circuits.md). We will go from truth conditions (i.e.
-We will go from truth conditions (i.e. what we want the circuit to do and when
+what we want the circuit to do and when we want it to do it) to a function
-we want it to do it) to a function expression which is then reduced to its
+expression which is then reduced to its simplest form and implemented with
-simplest form and implemented with
+[logic gates](Logic_gates.md). Specifically, NAND gates.
-[logic gates](Logic_gates.md).
-Specifically, NAND gates.
 
 We will show here that a complex logical expression can be reduced to an
 equivalent expression that uses only the NAND operator.
@@ -120,10 +115,8 @@ $$
 | 1   | 1   | 1          | 1                               |
 
 Finally, we can simplify even further by doing away with AND and NOT and using a
-single
+single [NAND gate](Logic_gates.md#nand-gate) which embodies the logic of both,
-[NAND gate](Logic_gates.md#nand-gate)
+being true in all instances where AND would be false: $\lnot (x \land  y)$.
-which embodies the logic of both, being true in all instances where AND would be
-false: $\lnot (x \land  y)$.
 
 Let's prove the theorem that every logical expression can be formulated as a
 NAND function. To do this we need to show that both NOT and AND can be converted

zk/Call_stack.md

@@ -31,7 +31,3 @@ console.log("Bye");
    function: the `console.log("bye")`
 6. Executes
 7. Returns to line that called it. Finds nothing else to do. Exits program.
-
-## Related notes
-
-![Stack memory](Stack_memory.md)

zk/Chipset_and_controllers.md

@@ -4,8 +4,6 @@ tags:
   - computer-architecture
 ---
 
-# Chipset and controllers
-
 A **controller** is simply a circuit that controls a process. The **chipset** is
 a combination of controllers placed on the same piece of silicon.
 

zk/Concise_subfield_mapping_JS.md

@@ -4,8 +4,6 @@ tags: []
 created: Friday, June 28, 2024
 ---
 
-# Concise mapping of object subfields in JS
-
 ## Scenario
 
 You have an array of objects and you want to return the objects with only a
@@ -33,5 +31,3 @@ More concise approach with destructuring:
 ```js
 const subset = arrayOfObjs.map(({ name }) => ({ name }));
 ```
-
-## Related notes

zk/Conditionals_in_Bash.md

@@ -3,8 +3,6 @@ tags:
   - shell
 ---
 
-# Conditionals in Bash
-
 ## If statements
 
 - Conditional blocks start with `if` and end with the inversion `fi` (this is a

zk/Creating_a_Linux_partition_table.md

@@ -146,7 +146,3 @@ sudo e2label /dev/sda1 my_human_name
 > Whilst we have created our partitions we cannot yet mount them. This is
 > because we have not yet set up a filesystem on the partitions. This is the
 > next step.
-
-## Related notes
-
-![Linux disk partitions](./Linux_disk_partitions.md)

zk/Current.md

@@ -2,8 +2,6 @@
 tags: [physics, electricity]
 ---
 
-# Current
-
 > Electrical current is the movement of electrons from negatively charged atoms
 > to positively charged atoms when an appropriate external force is applied.
 

zk/Delay_line_memory.md

@@ -3,8 +3,6 @@ tags: [computer-history, memory]
 created: Wednesday, September 18, 2024
 ---
 
-# Delay line memory
-
 - First described in the _First Draft_ by #vonNeumann based on work by Eckert
   and Mauchley.
 

zk/Delete_and_replace_characters_from_stdout_with_tr.md

@@ -4,8 +4,6 @@ tags:
   - procedural
 ---
 
-# Delete and replace characters from stdout with `tr`
-
 I used the following pattern to remove new lines and blank spaces:
 
 ```sh

zk/Docker_volumes.md

@@ -3,8 +3,6 @@ tags: [docker]
 created: Sunday, May 04, 2025
 ---
 
-# Docker volumes
-
 > This is a WIP re-write of [Docker Storage](./Docker_storage.md).
 
 ## _Bind mounts_ versus _named volumes_

zk/DynamoDB_CLI_commands.md

@@ -4,8 +4,6 @@ tags: [AWS, databases, dynamodb]
 created: Saturday, June 22, 2024
 ---
 
-# DynamoDB CLI commands
-
 ## Connecting to a local (Docker)/prod (AWS) DynamoDB instance
 
 In order to distinguish between local and production accounts you should keep
@@ -65,5 +63,3 @@ aws dynamodb scan \
 --table-name TimeEntries \
 --output table
 ```
-
-## Related notes

zk/DynamoDB_SDK_commands.md

@@ -4,8 +4,6 @@ tags: [AWS, databases, dynamodb]
 created: Sunday, June 23, 2024
 ---
 
-# DynamoDB SDK commands
-
 The following commands are for using `@aws-sdk/client-dynamodb` (the JS SDK).
 
 ## Create client
@@ -76,5 +74,3 @@ const params = {
 const dynamoDbDocumentClient = DynamoDBDocumentClient.from(client);
 const data = await dynamoDbDocumentClient.send(new ScanCommand(params));
 ```
-
-## Related notes

zk/DynamoDB_data_structure.md

@@ -7,8 +7,6 @@ tags:
 created: Sunday, June 09, 2024
 ---
 
-# DynamoDB
-
 ## Data structure
 
 ### Non-relational tables
@@ -129,5 +127,3 @@ I have also defined a GSI. This is derived from the `Year` attribute. This will
 group all the items by their `Year`, allowing me to query directly by year but
 also helping to chunk the entries which will make look-ups quicker and less
 expensive.
-
-## Related notes

zk/Expansions_and_substitutions.md

@@ -3,8 +3,6 @@ tags:
   - shell
 ---
 
-# Expansions and substitutions
-
 Bash is weird in that parentheses, braces and brackets are used not just as
 markers for different code blocks but as the designators of commands in their
 own right. The type of bracket you use effects how your input is interpreted.
@@ -79,10 +77,9 @@ the second list against them.
 ## Parameter expansion: `${...}`
 
 We use most frequently for returning the value of stored
-[variables](Variables_and_data_types_in_Bash.md).
+[variables](Variables_and_data_types_in_Bash.md). Techically we do not have to
-Techically we do not have to use the braces, we can retrieve with just `$var`
+use the braces, we can retrieve with just `$var` however it's better to use them
-however it's better to use them to minimise interpretation fuck-ups which happen
+to minimise interpretation fuck-ups which happen a lot.
-a lot.
 
 When the braces are used, this allows us to transform the values before they are
 returned such as only returning from the 6th character: `${var:6}`.
@@ -91,8 +88,7 @@ returned such as only returning from the 6th character: `${var:6}`.
 
 Command substitution (circle-brackets) allows us to put the output of one
 command inside another. Bash runs the bracketed command in a
-[sub-shell](Shell_sessions.md) and then returns it
+[sub-shell](Shell_sessions.md) and then returns it to the main user shell.
-to the main user shell.
 
 For example:
 
@@ -104,6 +100,4 @@ echo "The current directory is $(pwd)."
 
 We use arithmetic expansion when we want to calculate numerical values
 
-See
+See [Working with numbers in Bash](Working_with_numbers_in_Bash.md) for more.
-[Working with numbers in Bash](Working_with_numbers_in_Bash.md)
-for more.

zk/Firewalls.md

@@ -3,8 +3,6 @@ tags: [networks, servers, firewalls]
 created: Sunday, February 09, 2025
 ---
 
-# Firewalls
-
 A firewall is a server mechanism that filters incoming requests for resources
 and services that it hosts.
 

zk/Forgejo_runner_failure_after_VPS_reboot.md

@@ -3,8 +3,6 @@ tags: [docker, servers]
 created: Saturday, August 09, 2025
 ---
 
-# Forgejo runner failure after VPS reboot
-
 If you get stuck on "Waiting" when running an automated deployment in Forgejo,
 this can be because you've rebooted the VPS and the Docker permissions have
 reset.

zk/Global_object_in_NodeJS.md

@@ -3,8 +3,6 @@ tags:
   - node-js
 ---
 
-# Global object
-
 > In Node every function and variable should be scoped to a module. We should
 > not define functions and variables within the global scope.
 

zk/Grep.md

@@ -3,8 +3,6 @@ tags:
   - shell
 ---
 
-# Grep
-
 ## Purpose of `grep`
 
 `grep` stands for “global regular expression print”. It allows you to search

zk/Headless_Raspi_network_setup.md

@@ -8,8 +8,6 @@ tags:
 created: Wednesday, June 12, 2024
 ---
 
-# Headless network setup
-
 If you are using a headless system and you aren't using an ethernet connection,
 you face a chicken-egg issue of how to connect the device to WiFi via `ssh` when
 the device isn't yet on the network.
@@ -31,5 +29,3 @@ network={
      key_mgmt=WPA-PSK
 }
 ```
-
-## Related notes

zk/Heap_memory.md

@@ -4,10 +4,8 @@ tags: [memory, C]
 created: Saturday, April 20, 2024
 ---
 
-# Heap memory
+Along with [stack memory](/zk/Stack_memory.md), programs make use of _heap
-
+memory_ during runtime.
-Along with [[Stack_memory|Stack memory]], programs make use of _heap memory_
-during runtime.
 
 Heap memory does not use a standardised data structure and can be accessed from
 any point within the program.
@@ -36,5 +34,3 @@ The `malloc` method requests 512 bytes that it wants to assign to the `data`
 variable. It will return the address of the first byte in the newly allocated
 memory. `data` will then refer to the address on the stack that holds the
 address allocation on the heap.
-
-## Related notes

zk/Intro_to_the_Unix_shell.md

@@ -3,8 +3,6 @@ tags:
   - shell
 ---
 
-# Introduction to the Unix shell
-
 ## Unix based systems
 
 Many operating systems are based on the UNIX software architecture. macOS/OSX

zk/Invoking_the_shell_in_Python.md

@@ -4,8 +4,6 @@ tags: [python, shell]
 created: Monday, April 29, 2024
 ---
 
-# Invoking the shell in Python
-
 ```py
 import subprocess
 

zk/Lambda_programming_model.md

@@ -4,8 +4,6 @@ tags:
   - aws-lambda
 ---
 
-# AWS Lambda programming model
-
 The overall architecure consists in the following three processes:
 
 1. Triggers
@@ -18,8 +16,7 @@ See [AWS Lambda triggers](Lambda_triggers.md)
 
 ## Handler function
 
-See
+See [AWS Lambda handler function](Lambda_handler_function.md)
-[AWS Lambda handler function](Lambda_handler_function.md)
 
 ## Code
 

zk/Linux_disk_partitions.md

@@ -5,8 +5,6 @@ tags:
   - procedural
 ---
 
-# Linux disk partitions
-
 A disk is divided up into partitions which are subsections of the overall disk.
 The kernel presents each partition as a [block device](Devices.md#Devices) as it
 would with an entire disk.
@@ -96,8 +94,8 @@ The two tools disclose that the main harddrive is `/dev/nvme0n1` (equivalent to
 
 - The root partition is vital for the system's functionality. Without it, the
   system cannot boot or operate. It needs to be  
-   large enough to accommodate the operating system, installed programs, and system
+   large enough to accommodate the operating system, installed programs, and
-  libraries, but it doesn't need to store user data or  
+  system libraries, but it doesn't need to store user data or  
    additional applications, which can be located on other partitions.
 
 - This is the domain of the [superuser](User_Space.md#root-user-superuser). The
@@ -171,7 +169,3 @@ In our example above:
     </ul>
 </dd>
 </dl>
-
-## Related notes
-
-![Creating a Linux partition table](./Creating_a_Linux_partition_table.md)

zk/Listing_and_navigating_directories_in_the_Shell.md

@@ -3,8 +3,6 @@ tags:
   - shell
 ---
 
-# Listing and navigating directories in the shell
-
 ## Listing options
 
 Obviously we know that in order to list the files and sub-directories in our

zk/Logical_possibility_and_necessity.md

@@ -4,19 +4,17 @@ tags:
   - logic
 ---
 
-# Logical possibility and necessity
-
 ## Logical possibility
 
 In distinguishing the properties of
 [logical consistency](Logical_consistency.md) and
-[validity](Validity_and_entailment.md) we make tacit use
+[validity](Validity_and_entailment.md) we make tacit use of the notion of
-of the notion of **possibility**. This is because when we consider the validity
+**possibility**. This is because when we consider the validity of an argument we
-of an argument we are assessing truth-conditions and this consists in asking
+are assessing truth-conditions and this consists in asking ourselves what could
-ourselves what could or could not be the case: were it such that _P_, then it
+or could not be the case: were it such that _P_, then it would be the case that
-would be the case that _Q_. It is important to understand what possibility means
+_Q_. It is important to understand what possibility means in the context of
-in the context of logic and how it differs from what we might mean ordinarily
+logic and how it differs from what we might mean ordinarily when we use the
-when we use the term.
+term.
 
 It is evident from the case of arguments that are valid but not sound that logic
 operates with a specialised notion of possibility. For example it has to be the
@@ -60,9 +58,9 @@ From this we can derive the following property of logical possibility:
 A proposition is _logically necessary_ if it is true in every logically possible
 circumstance which is to say: true on every possible truth functional
 assignment. Necessity and
-[logical truth](Logical_truth_and_falsity.md#logical-truth)
+[logical truth](Logical_truth_and_falsity.md#logical-truth) are therefore
-are therefore synonyms: anything that is logically true (a tautology) is true by
+synonyms: anything that is logically true (a tautology) is true by necessity
-necessity (could not be otherwise.)
+(could not be otherwise.)
 
 Further, every logical truth is logically possible but not everything that is
 logically possible is logically true. It is possible that it is raining but this

zk/Magnetic_core_memory.md

@@ -3,8 +3,6 @@ tags: [computer-history, memory]
 created: Friday, September 27, 2024
 ---
 
-# Magnetic core memory
-
 ![](../img/magnetic-core-memory.jpg)
 
 Like [Magnetic_drum_memory](Magnetic_drum_memory.md), magnetic core memory was

zk/Processes.md

@@ -4,8 +4,6 @@ tags: [operating-systems]
 created: Friday, June 21, 2024
 ---
 
-# Processes
-
 Programs are sequences of machine instructions stored in a file. However they do
 not work by themselves. Something needs to load the file's intructions into
 memory, direct the CPU to run the program and manage it during runtime. The OS
@@ -46,11 +44,3 @@ therefore also a child (grandchild) of `terminator`.
 
 Each process has a unique identifier called a _process identifier_, a
 _processID_ or just _PID_.
-
-## Related notes
-
-![systemd](./systemd.md)
-
-![ps](./ps.md)
-
-![Monitoring processes and resources](Monitoring_processes_and_resources.md)

zk/Push_buttons.md

@@ -4,8 +4,6 @@ tags: [electronics]
 created: Tuesday, June 25, 2024
 ---
 
-# Push buttons
-
 Push buttons are push-to-make switches. This means that they are **on when they
 pressed and off when they are not pressed**. A classic example would be the
 switches on a keyboard.
@@ -30,7 +28,3 @@ _The push button being used as simple connector which does not break the
 circuit:_
 
 ![](../img/incorrect_push_button.jpg)
-
-## Related notes
-
-https://projects.raspberrypi.org/en/projects/button-switch-scratch-pi/1

zk/Querying_a_Mongo_collection.md

@@ -6,8 +6,6 @@ tags:
   - databases
 ---
 
-# Query a Mongo collection with Mongoose
-
 We now have the following entries in our `courses` collection:
 
 ```js
@@ -35,8 +33,8 @@ We now have the following entries in our `courses` collection:
 
 Now we will query the collection. This capability is provided via the Mongoose
 schema class we used to create the `Course`
-[model](Create_collections_and_documents_with_Mongoose.md#models).
+[model](Create_collections_and_documents_with_Mongoose.md#models). We have the
-We have the following methods available to use from the schema:
+following methods available to use from the schema:
 
 - `find`
 - `findById`

zk/ROM_versus_disk_loading.md

@@ -4,8 +4,6 @@ tags: [computer-architecture, memory]
 created: Monday, June 24, 2024
 ---
 
-# ROM versus disk loading
-
 I will explore the concept via the practical examples of cartridge-based and
 disk-based video games console.
 
@@ -54,5 +52,3 @@ to take that disk and load it on another Xbox, it would not include any of the
 expansions or updates. The game would function in its original form, as the
 additional content and updates reside solely on the hard drive of the first
 console where they were downloaded.
-
-## Related notes

zk/Signed_and_unsigned_numbers.md

@@ -3,17 +3,9 @@ tags:
   - binary
 ---
 
-# Signed and unsigned numbers
-
-## Summary
-
 - To represent negative integers in binary we use signed numbers._Signed binary_
   includes negative integers, _unsigned binary_ does not.
 
 - There are different methods of implementing the encoding of signed numbers.
   Two prominant approaches are **two's complement** and **signed magnitude
   representation**.
-
-## Related notes
-
-[[Twos_complement]], [[Binary_encoding]], [[Signed_magnitude_representation]]

zk/Signed_magnitude_representation.md

@@ -5,8 +5,6 @@ tags:
 created: Wednesday, March 20, 2024
 ---
 
-# Signed magnitude representation
-
 ## Summary
 
 ## Detail
@@ -25,13 +23,3 @@ the furthest bit (aka. the "most significant bit" (MSB)) at the $2^8$ position
 is `0`, designating that the number is unsigned. The signed equivalent is
 `1000 0101`, with the MSB being `1` designating the number as signed. When we
 are working with signed numbers, the MSB is known as the **signed bit**.
-
-### Advantages
-
-### Limitations
-
-## Applications
-
-## Related notes
-
-[[Signed_and_unsigned_numbers|signed_and_unsigned_numbers]]

zk/Single_file_Python_scripts.md

@@ -4,8 +4,6 @@ tags: []
 created: Friday, April 26, 2024
 ---
 
-# Single file Python scripts
-
 ## Basic architecture
 
 ```py
@@ -38,7 +36,3 @@ if __name__ == "__main__":
     main()
 
 ```
-
-## Related notes
-
-![Python modules and imports](./Python_modules_and_imports.md)

zk/Syllogism.md

@@ -4,16 +4,14 @@ tags:
   - logic
 ---
 
-# Syllogism
-
 In order to make assertions about the relative
-[consistency](Logical_consistency.md) or inconsistency
+[consistency](Logical_consistency.md) or inconsistency of a set of propositions
-of a set of propositions we advance arguments. Consider everyday life: if we are
+we advance arguments. Consider everyday life: if we are having an argument with
-having an argument with someone, we believe that they are wrong. A more logical
+someone, we believe that they are wrong. A more logical way to say this is that
-way to say this is that we believe that their beliefs are inconsistent. In order
+we believe that their beliefs are inconsistent. In order to change their
-to change their viewpoint or point out why they are wrong we advance an argument
+viewpoint or point out why they are wrong we advance an argument intended to
-intended to show that belief A conflicts with belief B. Or if C is true, then
+show that belief A conflicts with belief B. Or if C is true, then you cannot
-you cannot believe that D.
+believe that D.
 
 In formal terms **an argument is a set of propositions comprising one or more
 premises and a conclusion. The conclusion is taken to be supported by the

zk/Threads.md

@@ -4,8 +4,6 @@ tags: [operating-systems]
 created: Wednesday, June 26, 2024
 ---
 
-# Threads
-
 A ![process](Processes.md) is a running instance of a given program. A program
 runs sequentially handling one task at a time, however we may need to run
 certain tasks in parallel.
@@ -36,7 +34,3 @@ the number of cores that a device's CPU has deterimines how many threads can run
 at once. In practice, then, the CPU shuffles between multiple threads in
 [clock segments](Clock_signals.md). This is known as scheduling and is managed
 by the process that the thread belongs to.
-
-## Related notes
-
-![Processes](Processes.md)

zk/Twos_complement.md

@@ -92,8 +92,3 @@ $$
   bit length of the system
 
 - Consequently two's complement can necessitate larger overall word lengths.
-
-## Related notes
-
-[[Signed_and_unsigned_numbers|signed_and_unsigned_numbers]],
-[[Binary_addition|binary addition]], [[Signed_magnitude_representation]]

zk/journald.md

@@ -5,8 +5,6 @@ tags:
   - procedural
 ---
 
-# `journald`
-
 `journald` is a program that comes as default with [systemd](systemd.md). It is
 a service for collecting and storing system-level log data. I keeps a track of
 all [kernel](The_kernel.md) processes. It is invaluable when tracing the source