3 ms·

> But I think it would be helpful for many people to first learn logic and deduction "the precise way", and then do actual mathematical proof where you can jump

> But I think it would be helpful for many people to first learn logic and deduction "the precise way", and then do actual mathematical proof where you can jump over more obvious parts. Absolutely. And I can not imagine a mathematics degree which doesn't place formal logic front and center in the first semester. When you are starting out you absolutely need to suffer through the rigourous formal arguments. >Ironically, the one subject which often teaches formal logic as an early introductory class for undergraduates isn't mathematics, computer science, or physics, it's philosophy. I can not believe that this is the case. Even engineering undergrads have to learn formal logic in their first semester.

141205 3y ago
> Even engineering undergrads have to learn formal logic in their first semester. I got my engineering B.S. from a top 5 college in the US, and have known many people who have gone to similar schools. None of us have had to take a class that goes into first order logic or proof writing. I don't know what college you go to where that is a thing, but it would be exceedingly rare.
- constantcrying 3y ago
  >I don't know what college you go to where that is a thing, but it would be exceedingly rare. German technical university. I was a tutor there. AFAIK this is normal. As part of the first semester you take linear algebra and analysis, starting out with the basics of formal logic. Of course the courses are less focused on proof writing than the mathematics "major" courses. I should also point out that German universities have very loose entry standards (except when places are very rare compared to applicants) and use the first two semesters to filter out students. These courses are often designed to have around a 50% failure rate.
  - Solvency 3y ago
    Your student filtration system sounds like a long and expensive waste of everyone's time.
    - constantcrying 3y ago
      Not really. First year courses usually have hundreds of students in large halls. There is some more effort as you need more tutors, but that is basically it. (Students usually do not live on campus) The enormous upside is that all students are judged equally on their ability to academically succeed in their chosen field. I think US university admissions are ridicolous for many reasons.
  - l33t233372 3y ago
    > As part of the first semester you take linear algebra and analysis, starting out with the basics of formal logic There is not enough time to learn the basics of formal logic and linear algebra and/or analysis in a single class, but I think what you’re referring to is an introduction to proof techniques like induction, modus tollens, quantifiers, etc. Every math and computer science department in the US that I’ve ever heard of teaches these topics, but I wouldn’t call it a formal logic class.
    - constantcrying 3y ago
      For me basic formal logics means learning the symbols (conjunction, disjunction, implication, equivalency, not, etc.) and the rules of inference to maniuplate these symbols and using these rules to prove new things. How can you teach analysis without that anyway. It is absolutely essential for set theory and how would you e.g. define the reals (in a "proper" math course, not engineering) without a good understanding of set theory? If you don't believe me, here is a link to the contents of a first semester engineering math course from some german technical university: https://page.math.tu-berlin.de/~joswig/teaching/notes/Joswig-LineareAlgebra-08_09.pdf https://page.math.tu-berlin.de/~joswig/teaching/notes/Joswig... The symbols should be enough to tell you what the contents are.
      - Tainnor 3y ago
        > For me basic formal logics means learning the symbols (conjunction, disjunction, implication, equivalency, not, etc.) and the rules of inference to maniuplate these symbols and using these rules to prove new things. That's really only baby logic. Which, probably, is what will be sufficient for most mathematician most of the time. A real first introduction to formal logic would introduce an actual formal proof system and go at least as far as proving completeness of first order logic.
        constantcrying 3y ago
        >That's really only baby logic. Instead of (literally) infantalizing the name, you could also call it basic formal logic.
- daniel-cussen 3y ago
  [dead]
sukilot 3y ago
Formal logic is taught in Mathematical Logic class (intermediate, optional) or Discrete math (intro/intermediate, often not taken) Geometry class in high school sometimes teaches some of it. Computer science Binary logic teaches some of (De Morgan's laws) Outside of New Math of the 1970s, it is a glaring omission from the curriculum. Even enriched classes like Art of Problem Solving that put heavy emphasis on proofs, do not teach formal logic.
- cubefox 3y ago
  To be fair, I think some people just quickly and intuitively "get" what's expected from them when doing proofs, without any formal introduction. But for others (like me) it is very much helpful to at least list the basic natural deduction inference rules, and to do a bunch of exercises where they have to use these rules explicitly. Otherwise they are floating in thin air, with only a hazy idea of what a "valid logical step" even is.

141205 3y ago

> Even engineering undergrads have to learn formal logic in their first semester. I got my engineering B.S. from a top 5 college in the US, and have known many people who have gone to similar schools. None of us have had to take a class that goes into first order logic or proof writing. I don't know what college you go to where that is a thing, but it would be exceedingly rare.

constantcrying 3y ago
>I don't know what college you go to where that is a thing, but it would be exceedingly rare. German technical university. I was a tutor there. AFAIK this is normal. As part of the first semester you take linear algebra and analysis, starting out with the basics of formal logic. Of course the courses are less focused on proof writing than the mathematics "major" courses. I should also point out that German universities have very loose entry standards (except when places are very rare compared to applicants) and use the first two semesters to filter out students. These courses are often designed to have around a 50% failure rate.
- Solvency 3y ago
  Your student filtration system sounds like a long and expensive waste of everyone's time.
  - constantcrying 3y ago
    Not really. First year courses usually have hundreds of students in large halls. There is some more effort as you need more tutors, but that is basically it. (Students usually do not live on campus) The enormous upside is that all students are judged equally on their ability to academically succeed in their chosen field. I think US university admissions are ridicolous for many reasons.
- l33t233372 3y ago
  > As part of the first semester you take linear algebra and analysis, starting out with the basics of formal logic There is not enough time to learn the basics of formal logic and linear algebra and/or analysis in a single class, but I think what you’re referring to is an introduction to proof techniques like induction, modus tollens, quantifiers, etc. Every math and computer science department in the US that I’ve ever heard of teaches these topics, but I wouldn’t call it a formal logic class.
  - constantcrying 3y ago
    For me basic formal logics means learning the symbols (conjunction, disjunction, implication, equivalency, not, etc.) and the rules of inference to maniuplate these symbols and using these rules to prove new things. How can you teach analysis without that anyway. It is absolutely essential for set theory and how would you e.g. define the reals (in a "proper" math course, not engineering) without a good understanding of set theory? If you don't believe me, here is a link to the contents of a first semester engineering math course from some german technical university: https://page.math.tu-berlin.de/~joswig/teaching/notes/Joswig-LineareAlgebra-08_09.pdf https://page.math.tu-berlin.de/~joswig/teaching/notes/Joswig... The symbols should be enough to tell you what the contents are.
    - Tainnor 3y ago
      > For me basic formal logics means learning the symbols (conjunction, disjunction, implication, equivalency, not, etc.) and the rules of inference to maniuplate these symbols and using these rules to prove new things. That's really only baby logic. Which, probably, is what will be sufficient for most mathematician most of the time. A real first introduction to formal logic would introduce an actual formal proof system and go at least as far as proving completeness of first order logic.
      - constantcrying 3y ago
        >That's really only baby logic. Instead of (literally) infantalizing the name, you could also call it basic formal logic.
daniel-cussen 3y ago
[dead]

sukilot 3y ago

Formal logic is taught in Mathematical Logic class (intermediate, optional) or Discrete math (intro/intermediate, often not taken) Geometry class in high school sometimes teaches some of it. Computer science Binary logic teaches some of (De Morgan's laws) Outside of New Math of the 1970s, it is a glaring omission from the curriculum. Even enriched classes like Art of Problem Solving that put heavy emphasis on proofs, do not teach formal logic.

cubefox 3y ago
To be fair, I think some people just quickly and intuitively "get" what's expected from them when doing proofs, without any formal introduction. But for others (like me) it is very much helpful to at least list the basic natural deduction inference rules, and to do a bunch of exercises where they have to use these rules explicitly. Otherwise they are floating in thin air, with only a hazy idea of what a "valid logical step" even is.