## UnkleRhaukus 3 years ago which subtopic of maths does logic go in/

1. estudier

Metamath (for mathematical logic)

2. UnkleRhaukus

if you say so

3. estudier

Don't u believe me?:-)

4. UnkleRhaukus

i dont really know what defines metamath

5. ParthKohli

It comes under Pure Mathematics. @estudier is telling you to ask them in the Meta-math group.

6. ParthKohli

Mathematical logic per se is a study which comes under Pure Mathematics.

7. estudier

Roughly speaking it is the use of math to talk about math.

8. UnkleRhaukus

what ever you reckon

9. ParthKohli

Because they have no mathematical logic group, meta-math is the best group to ask in. In fact, Meta-math is an appropriate description of mathematical logic, because it's mathematics about mathematics.

10. estudier

To be honest, I am not so sure that we really need this section in OS. At least, I think that there would not be so many members of that group.

11. UnkleRhaukus

but logic about logic is maths

12. ParthKohli

Yeah... it's sort of a conclave thing.

13. estudier

One thing I noticed missing is a Miscellaneous/Other category or a category for Recreational Mathematics

14. estudier

Anyway, that is not the question here, sorry...

15. estudier

I think it is a good idea to ask the question in the metamath group "What is metamath?" (And pin the thread, except u can't do that)

16. UnkleRhaukus

well so far i have some reason to post logic questions in the subtopic metamath, however i can think of equally valid reasons to post logic question in other subtopics, so i still am not convinced that metamath is the best section to post in

17. estudier

Where would you post it instead? Algebra? (I don't disagree with u, metamath only includes mathematical logic usually)

18. UnkleRhaukus

probability, statistics, discrete math

19. UnkleRhaukus

geometry

20. estudier

Exactly which sort of logic are we talking about?

21. UnkleRhaukus

where do you think is best for this question $(1,2)\cap[2,3)=$

22. estudier

Set Theory = Metamath Applications of Set theory = The area in which it is being applied.

23. UnkleRhaukus

im talking about these operators $$\neg,\land,\lor,\Rightarrow,\Leftrightarrow,\exists,\forall,|$$

24. estudier

Again, you have to distinguish between the theory and the applications

25. estudier

The theory is that of formal systems (First order logic and in general, nth order logics).

26. UnkleRhaukus

well im doing a course you see, and we have covered all the above operators , then some stuff on proof, ( like proof of $$\sqrt{2}\not\in\mathbb Q\}$$ and now we are starting some set theory

27. estudier

Yes, these are all connected...

28. UnkleRhaukus

$\{,(,[,\cup,\cap,$

29. UnkleRhaukus

i feel there should be a single subtopic that can accommodate all these, maybe it is just maths

30. estudier

propositional logic - simple declarative propositions, first-order logic - covers predicates and quantification as well

31. estudier

These are then used in ZFC (a formal mathematical system) to prove things using the language of sets

32. estudier

At a very abstract level, I would call this metamath. Otherwise, it would depend on where it was being applied.

33. UnkleRhaukus

yeah

34. estudier

However it does seem to be to be very algebraic in nature.

35. UnkleRhaukus

my main reason for disliking metamath as the best option, is that the OS group dosent have much history of use of these symbols

36. estudier

Basically, I agree, we could get along fine without this subgroup and instead maybe have one called "Proofs, Logic and Sets" or something like that.

37. lgbasallote

logic is under discrete mathematics......

38. estudier

I have seen people say that logic (and set theory/proofs) is a part of discrete math but I fail to see why that should be, logic, proof and set theory is applied across all of mathematics.

39. lgbasallote

if you consider logic to be under mathematics, then it's under discrete mathematics. Otherwise, you might as well consider logic to be under philosophy

40. estudier

If it is the theory of mathematical logic then it is definitely metamathematics, the applications could be anywhere but to me the usage seems most like algebra (symbolic manipulation according to some rules). There are a lot of things under the heading "logic", it depends what u mean and whether you are talking about applications or theory.

That's a good question. Keep in mind that if you can't find a valid subtopic, you can absolutely just post it directly in math. That said, you're right that set theory and formal logic could probably use some sort of subtopic. I feel like lumping proofs in there is random and unnecessary, however (despite the fact that proofs often rely on formal logic). Perhaps a logic & sets topic? The correlation there is stronger, I feel.

42. swissgirl

Well Discrete math is basically compromised of Logic, Set Theory, Relations, Cardinality, Functions such as mapping a function onto or one to one and sometimes graph theory. So I guess you would ask a logic question in the Discrete math section.

43. estudier

@swissgirl Well (deleted) math is basically compromised of Logic, Set Theory, Relations, Cardinality, Functions such as mapping a function onto or one to one and sometimes graph theory. So I guess you would ask a logic question in the (deleted) math section. :-)

44. swissgirl

As usual I didnt follow the joke lol