14 Matching Annotations
  1. Last 7 days
    1. My freely downloadable Beginning Mathematical Logic is a Study Guide, suggesting introductory readings beginning at sub-Masters level. Take a look at the main introductory suggestions on First-Order Logic, Computability, Set Theory as useful preparation. Tackling mid-level books will help develop your appreciation of mathematical approaches to logic.

      This is a reference to a great book "Beginning Mathematical Logic: A Study Guide [18 Feb 2022]" by Peter Smith on "Teach Yourself Logic A Study Guide (and other Book Notes)". The document itself is called "LogicStudyGuide.pdf".

      It focuses on mathematical logic and can be a gateway into understanding Gödel's incompleteness theorems.

      I found this some time ago when looking for a way to grasp the difference between first-order and second-order logics. I recall enjoying his style of writing and his commentary on the books he refers to. Both recollections still remain true after rereading some of it.

      It both serves as an intro to and recommended reading list for the following: - classical logics - first- & second-order - modal logics - model theory<br /> - non-classical logics - intuitionistic - relevant - free - plural - arithmetic, computability, and incompleteness - set theory (naïve and less naïve) - proof theory - algebras for logic - Boolean - Heyting/pseudo-Boolean - higher-order logics - type theory - homotopy type theory

  2. Nov 2022
    1. Hashie does not have built-in support for coercing boolean values, since Ruby does not have a built-in boolean type or standard method for coercing to a boolean. You can coerce to booleans using a custom proc.

      I use: ActiveRecord::Type::Boolean.new.cast(value)

    1. You can do searches that exclude certain labels. That is, searches like this will do what you expect: (label:MyLabel1 AND NOT label:inbox AND NOT label:MyBadLabel1) That search will show you only messages that: Do have MyLabel1 And do not have label inbox And do not have label MyBadLabel1 The tricks are: to get yourself out of conversation mode! (As @Ruben says above.) to use UPPER CASE for the logic operators (AND NOT will work, and not won't) If you leave "conversation mode" on, you will get confusing results. For example, doing that search above (with conversation mode on), will likely return messages that do NOT match your search. It may be a bit weird. Here's the deal: Conversations are collections of messages that all have the same Subject. When "conversation mode" is on, searches return entire conversations as results. So what should gmail search do if a conversation contains both a message that matches, and a message that does not match your search? You are probably expecting it to return conversations only if all messages in that conversation match. But that is not correct. Instead, Gmail search will return conversations even if only a single message in that conversation matches. So that means that if you do the same search above with "conversation mode" on, the results are likely to include messages that do not match your search!

      I came here looking for a way to exclude certain emails from searches in Gmail. I was trying to make sure some emails that were archived don't show up, and this approach works (but the Boolean operators must be capitalized):

      (label:label_I_want AND NOT label:label_I_dont)

      If the unwanted label msgs are a part of a conversation thread containing the wanted msgs, then I'll need to turn this off first:

      Go to the main Settings page, look for the “Conversation View” section, select the option to turn it off, and save changes. If you change your mind, you can always go back. source

  3. Oct 2022
    1. https://www.loom.com/share/a05f636661cb41628b9cb7061bd749ae

      Synopsis: Maggie Delano looks at some of the affordances supplied by Tana (compared to Roam Research) in terms of providing better block-based user interface for note type creation, search, and filtering.

      These sorts of tools and programmable note implementations remind me of Beatrice Webb's idea of scientific note taking or using her note cards like a database to sort and search for data to analyze it and create new results and insight.

      It would seem that many of these note taking tools like Roam and Tana are using blocks and sub blocks as a means of defining atomic notes or database-like data in a way in which sub-blocks are linked to or "filed underneath" their parent blocks. In reality it would seem that they're still using a broadly defined index card type system as used in the late 1800s/early 1900s to implement a set up that otherwise would be a traditional database in the Microsoft Excel or MySQL sort of fashion, the major difference being that the user interface is cognitively easier to understand for most people.

      These allow people to take a form of structured textual notes to which might be attached other smaller data or meta data chunks that can be easily searched, sorted, and filtered to allow for quicker or easier use.

      Ostensibly from a mathematical (or set theoretic and even topological) point of view there should be a variety of one-to-one and onto relationships (some might even extend these to "links") between these sorts of notes and database representations such that one should be able to implement their note taking system in Excel or MySQL and do all of these sorts of things.

      Cascading Idea Sheets or Cascading Idea Relationships

      One might analogize these sorts of note taking interfaces to Cascading Style Sheets (CSS). While there is the perennial question about whether or not CSS is a programming language, if we presume that it is (and it is), then we can apply the same sorts of class, id, and inheritance structures to our notes and their meta data. Thus one could have an incredibly atomic word, phrase, or even number(s) which inherits a set of semantic relationships to those ideas which it sits below. These links and relationships then more clearly define and contextualize them with respect to other similar ideas that may be situated outside of or adjacent to them. Once one has done this then there is a variety of Boolean operations which might be applied to various similar sets and classes of ideas.

      If one wanted to go an additional level of abstraction further, then one could apply the ideas of category theory to one's notes to generate new ideas and structures. This may allow using abstractions in one field of academic research to others much further afield.

      The user interface then becomes the key differentiator when bringing these ideas to the masses. Developers and designers should be endeavoring to allow the power of complex searches, sorts, and filtering while minimizing the sorts of advanced search queries that an average person would be expected to execute for themselves while also allowing some reasonable flexibility in the sorts of ways that users might (most easily for them) add data and meta data to their ideas.

      Jupyter programmable notebooks are of this sort, but do they have the same sort of hierarchical "card" type (or atomic note type) implementation?

  4. Jun 2021
  5. Jul 2019
  6. Mar 2019
    1. Which got McCulloch thinking about neurons. He knew that each of the brain’s nerve cells only fires after a minimum threshold has been reached: Enough of its neighboring nerve cells must send signals across the neuron’s synapses before it will fire off its own electrical spike. It occurred to McCulloch that this set-up was binary—either the neuron fires or it doesn’t. A neuron’s signal, he realized, is a proposition, and neurons seemed to work like logic gates, taking in multiple inputs and producing a single output. By varying a neuron’s firing threshold, it could be made to perform “and,” “or,” and “not” functions.

      I'm curious what year this was, particularly in relation to Claude Shannon's master's thesis in which he applied Boolean algebra to electronics.

      Based on their meeting date, it would have to be after 1940. And they published in 1943: https://link.springer.com/article/10.1007%2FBF02478259

  7. Jan 2018
    1. Default Value

      Please note that the values listed below are the default ones. An Option can represent a Boolean toggle flag (i.e. HeapDumpOnOutOfMemoryError, PrintConcurrentLocks). For such Options, '+' and '-' flags deal with Boolean toggling. In short:

      • '+' means Enable (or set to '1');
      • '-' means Disable (or set to '0').

      For example, in the table pertaining to Debugging Options, by default the -XX:-HeapDumpOnOutOfMemoryError is Disabled, because it has the - prepended to it. To actually Enable it, change that with +, yielding the variant -XX:+HeapDumpOnOutOfMemoryError.

  8. Apr 2016