Discrete Mathematics

[Shadow Eye31]

Hello there.

Probably not what someone expected in this section, but here it goes.

I am studying discrete mathematics of my own accord. As I have no professor, nor do any of my peers understand even the fundamentals of logic (seriously, how hard is it to tell me if A is a knight or a knave?), I am struggling to fully grasp and understand what I am teaching myself. It's most likely a long shot, but I figured perhaps someone here may have a firm enough grasp to help me as I move through the text book I have, or maybe point me to where I can find such help.

Before anyone suggests this, my job does not readily allow me to take regular college courses, online or otherwise, due to irregular work hours highly prone to change. So, no, I cannot take a course for this subject, nor do they even offer one where I live currently.

At the moment, I am merely seeing if there is someone who might be able to help me with my study. I have a fairly good grasp of propositions, though I am a bit frustrated when trying to translate from English to a proposition, but I have no concrete issues at this time. I am using Discrete Mathematics and Its Applications (Seventh Edition) as my reference, just finishing section 1.2 yesterday.

If anyone would like to throw up a hand and allow me to prod their brain from time to time when I'm confused about something I'm currently working on in regard to discrete mathematics, I'd be grateful.

[Blizzard]

I've had Discrete Mathematics when I was studying at the university so I might be able to help you out if you have some concrete questions.

[Aqua]

I used the same book last semester in my college class.

I didn't pay attention as much as I should have, but I think I still remember most of what we learned.
Not sure how far we got in the book though.  I think it was around chapter 9 or something.

[KK20]

I'm taking the first half of the class right now, but we're using the book by Richard Johnsonbaugh. Found the first chapter extremely easy, but 2 and 3 is still not locked in yet (I understand how to do proofs, it's trying to solve them that always creates troubles). On probability right now.

[Blizzard]

If you're doing propositional logic, then the only thing you have to keep in mind that if A then B, it doesn't necessarily mean that B will make A true. It's a "one-way road". That's one the few things that you have to pay attention to.

[Shadow Eye31]

The hardest part for me, and what's making me move so slow through the sections, is translating, honestly. If I have easy propositions like "If I get elected, chocolate will rain from the heavens", p -> q, I have no problems. Its when it goes into "Chocolate will rain from the heavens only if I get elected and Bill Cosby stops eating pudding or Hey Arnold! comes back on TV." That's the part I'm struggling with, translating all that into propositional conjunctions and the like. But I'm getting there.

[Blizzard]

Here's a trick.

Chocolate will rain from the heavens only if I get elected and Bill Cosby stops eating pudding or Hey Arnold! comes back on TV.

Chocolate will rain from the heavens only if I get elected and Bill Cosby stops eating pudding or Hey Arnold! comes back on TV.

X if A and B or C

if A and B or C then X

A & B | C -> X
where:
A = I get elected
B = Bill Cosby stops eating pudding
C = Hey Arnold! comes back on TV
X = Chocolate will rain from the heavens

[Apidcloud]

Here's a trick.

Chocolate will rain from the heavens only if I get elected and Bill Cosby stops eating pudding or Hey Arnold! comes back on TV.

Chocolate will rain from the heavens only if I get elected and Bill Cosby stops eating pudding or Hey Arnold! comes back on TV.

X if A and B or C

if A and B or C then X

A & B | C -> X
where:
A = I get elected
B = Bill Cosby stops eating pudding
C = Hey Arnold! comes back on TV
X = Chocolate will rain from the heavens

I totally agree with Blizzard's way to go for it. I also got a book, from last year - when I studied that on college - so if you need exercices or anything related to it, just tell me. I'll search for the book tomorrow and check if it also explains theory. Besides, are you guys familiar with truth tables or whatever they're called? I remember doing really long tables in order 2 get all possible results lol

[Shadow Eye31]

Besides, are you guys familiar with truth tables or whatever they're called? I remember doing really long tables in order 2 get all possible results lol

Truth tables are like this, right?

Proposition: A and B

A     B     Truth
T     F     F
F     F     F
F     T     F
T     T     T

Here's a trick.

Chocolate will rain from the heavens only if I get elected and Bill Cosby stops eating pudding or Hey Arnold! comes back on TV.

Chocolate will rain from the heavens only if I get elected and Bill Cosby stops eating pudding or Hey Arnold! comes back on TV.

X if A and B or C

if A and B or C then X

A & B | C -> X
where:
A = I get elected
B = Bill Cosby stops eating pudding
C = Hey Arnold! comes back on TV
X = Chocolate will rain from the heavens

That actually does help. A lot. Thanks! Maybe now I can make a bigger dent in this book.

[Apidcloud]

Well you're missing A and B relationship but you're using Intersection in that truth table case