Logic Definition and 1000 Threads

Homework Statement Consider the following question Adams is a boy who does not own a car. Mary dates only boys who own cars.Therefore Mary does not date Adams. Homework Equations The Attempt at a Solution My answer is like this... Let Bx=x is a boy. Ox=x owns car...

Hello. As I understand, in the classical logic it's impossible to "take", for example, the set of all sets. I was wondering: is it possible to create a logic where that is possible by changing some of the basic postulates by which logic works? Or is it impossible for all logics? Thank you.

I'm taking Abstract Algebra right now, and we just briefly covered Logic and Truth Tables. This is my first time in school to learn such things. http://i111.photobucket.com/albums/n149/camarolt4z28/IMG_20110712_195458.jpg 37. I understand. 39. I understand. 41. I don't understand...

Hi, I'm looking for a book about epistemology and another about logic. But preferably books that aren't too technical, because I want to read them more as a hobby rather than as homework. But not too simple either please! On epistemology I found...

I don't know much about this subject, so this is probably a very basic question. If I want to understand/explain something, I use inductive or deductive reasoning, which are parts of logic. For example, take this inductive reasoning: Every life form we know of depends on liquid water to exist...

Does anyone know/understand the different definitions for Inconsistency in Sentence Logic and in Predicate Logic? I know in Sentence Logic, that a sentence ( a Wff, actually) S is contradictory, if from S we can derive (using theorems of truth-functional logic ) a sentence of...

How exactly does math research work? Thanks for all the help! EDIT: Since it may vary by field, I'm asking about the logic area.

Homework Statement [PLAIN]http://img863.imageshack.us/img863/6634/quiz14.jpg Homework Equations None The Attempt at a Solution I say B or E but I can't find a reason to choose. I ignore the solution.

I need to use combinational logic to produce a high ouput for a certain range of values. I have and anaolgue signal which i have converted to a 12 bit digital signal, I need an LED to be turned on when the analogue signal is above a certain voltage. I have the digital value (101001110100 =...

"Mathematical Logic" by Cori and Lascar: Incomplete proof of Lemma 1.9? I have a question on the book "Mathematical Logic: Propositional calculus, Boolean Algebras, predicate calculus" by Rene Cori and Daniel Lascar. Proof of Lemma 1.9 given on...

I have a question on the textbook "Mathematical Logic: Propositional calculus, Boolean Algebras, predicate calculus" by Rene Cori and Daniel Lascar. This is not about an exercise but about the conceptual content of the book. So I did not post this in the "Coursework and Homework questions"...

How important is a solid (or better) understanding of Logic, especially Symbolic and Mathematical, for an aspiring mathematician? For a physicist? Other scientists? Are there variations in how important it is for Analysis, Topology and Algebra? A mathematically inclined physicist told me...

"The meter is the length of the path traveled by light in vacuum during a time interval of 1/299,792,458 of a second.Note that the effect of this definition is to fix the speed of light in vacuum at exactly 299,792,458 m/s." I don't understand this because how can you use a number based on...

Hi, I've looked everywhere for an explanation of this, including this forum, and none of them seem to satisfy the level of detail I am looking for. More specifically, I am interested in how processing units used a fixed setup of logic gates and transistors to perform universal computation...

I want to find out how computer language compilers works from hardware point of view. How logic gates are implemented using compilers? Can anyone suggest me a good reference book or website where I can find this information?

The question was to prove \sqrt{x+\sqrt{x}}-\sqrt{x-\sqrt{x}}>1, x>1 And I had two choices to go about this, I could have manipulated the expression \sqrt{x+\sqrt{x}}-\sqrt{x-\sqrt{x}} by multiplying numerator and denominator by its conjugate, squaring, manipulating etc. and getting an...

In both classical and quantum mechanics, there's a lattice called the logic of the physical system. In CM, it's the set of all subsets of phase space. In QM, it's the set of all closed subspaces of a Hilbert space. Sloppy presentations of this subject say that the members of the logic represent...

EDIT: I was being stupid and forgot the first diode would turn off after i worked out stuff for diode C, thanks anyway, solution found!Hi I'm having some trouble getting the correct output voltage when i model the diodes using a voltage ofset and resistors. A = 4V, B = 2V, C = 3V Using Voltage...

Half of the classes I want to take have it as a prereq, and it's not offered over the summer. Assuming my school allows it, I want to try to test out. What should I know to be prepared? Thanks, Tyler

I recently read about the unexpected hanging problem and I was so surprised that logic actually failed in determining the solution!:( Is this just an isolated exception, or are there more paradoxes like this? And more importantly, why does logic fail? Isn't there any way around this? I just...

I am confused ,whats wrong with the reasoning below ? assume that the black lines are parallel and red Line segments are defined between the black lines. for any point on one of the red line segments there exist only one point on the other one (the points that are touched by the lines...

Hi, I'm taking an intro logic class and though I'm comfortable with most propositional logic, predicate logic is confusing me. I joined the forum to ask this particular question that I've been stuck on for a while. Any help would be appreciated - I'm having trouble finding information on the web...

Greetings everyone, I have been teaching myself mathematical logic for amusement by going through Stephen Cole Kleene’s textbook, “Mathematical Logic”. I am stuck on the following problem (problem 13.2 on page 58, if you happen to have the book): Show that, if |- Am+1, then A1, … , Am |- B...

Greetings. I'm making some experiments with DTL circuits, and i wonder if i missed something obvious when piecing the bits and facts about it from around the net. Are there ways to reduce the number of elements in the circuit when multiple DTL gates are used? For example, here is a NAND...

I don't know a lot about PLD's so hopefully someone here can help me. Is there a relatively cheap PLD that can switch between 2 inputs every given amount of time, like every second or every 5 seconds? I'm just trying to find what I am looking for and can look up and read through the data...

Homework Statement Consider the truth table below. (a) Write an expression for the logic function that it represents, and simplify that expression as much as possible, showing all steps. (b) Draw a logic circuit implementing this. (c) Redesign your circuit to use only NOR gates...

Calculate final pH of 25 ml buffer 0.1 M CH3COOH/CH3COO, pH=3.50, after the addition of 1.00 ml of 0.1 M HCl. 3.50=4.75+log(base/3.16x10-4) Base = 1.78x10-5 M Acid = 3.16x10-4 M Mole base = 0.000712 - 0.0001 = 0.000612 Mole Acid = 0.01264 +0.0001 = 0.01274 Mole Acid...

The three equations below represent three different logic expressions using and, or and not gates of two boolean variables A and B. A boolean variable can take only one of two possible values: True or False. Which of the two expressions are identical, meaning that for any combination of A...

Hello, I want to draw the detailed logic level diagram for a basic computer. For this i found a software that will work which is microsoft visio 2010. But i m not satisfied with that because it has some limitations. Such as re-arranging the wires automatically and also the simulation...

If we have K_n denote the complete graph on n vertices, can anyone explain to me how to know how many substructures does K_n have?

Homework Statement Pidgeonhole principle: If kn+1 objects are placed in n pigeonholes, then some pigeohoe contains atleast k+1 objects. Homework Equations The Attempt at a Solution I completely understand this problem but I am not sure where or how to start. If there are n =...

Homework Statement [PLAIN]http://img408.imageshack.us/img408/5284/scan0003xp.jpg Homework Equations There are none? The Attempt at a Solution I have tried to solve this problem via making a graph, trying to outright solve the problem, i have also tried to assign variables, and...

I was discussing with my E&M professor the idea of faster than light information exchange, which of course we found to be impossible, it didn't take much analysis of the simultaneity of events as seen by Einstein to realize that faster information travel than light would completely change the...

We know that the laws of physics are unique to our universe, that is they only hold true in our spacetime. My question is about logic and if logic holds true outside our universe unlike the laws of physics. For example, if we say that x>y and z>x then we can conclude that z>y is true by logic...

I am a physics student new to the world of electronics and I have a question that may turn out to be very simple. What I am trying to design requires that a single output given some input be held in memory for a specified time despite any differing input being sent through during that time...

Why is the CMOS logic voltage exactly 3.3V, why not 3V or 3.5V?

"In particle physics, an elementary particle or fundamental particle is a particle believed not to have substructure; that is, it is believed not to be made up of smaller particles." -Wikipedia How does someone ever possibly (LOGICALLY) conclude that a particle is not made up of smaller...

Hello all :smile: I am a mechanical engineering student taking an introductory circuits course. I find the things we are doing in lab quite interesting, but I really lack a good understanding of what we are doing. We are currently building logic gates using BJTs. I have some basic...

Homework Statement What subsets of the real line R are definable in (R,<)? What subsets of the plane RxR are definable in (R,<)? Homework Equations A subset is definable if there is a formula in first order logic that is true only of the elements of that subset. For example, in the...

Do most students find it more difficult than analysis and abstract algebra?

So recently just in my spare times I've found an interest in logic gates such as the nand gates and nor gates and such and although most of it's logic, there's one thing i just couldn't figure out. Let's say you have a nand gate configuration consisting of two pmos and two nmos transistors as...

We have the following sentences which I translated them to FOL by using the language: Att(x) for "x attended the ceremony" Likes(x,y) for "x likes y" Rel(x,y) for "x is a relative of y" Ab(x) for "x is an abnormal relative" (a) Only all the normal relatives attended the wedding...

Homework Statement If there were three boxes, one box is made of apples, the other is made of organes, and the last is made of organes and apples. You are able to open only one box without looking in, and you are able to look at only one fruit inside the box. By looking at the fruit, how can...

Could anyone help me with this? Donald and Daisy Duck took their nephews, age 4, 5, and 6, on an outing. Each boy wore a tee-shirt with a different design on it and of a different color. You are also given the following information: ■ Huey is younger than the boy in the green tee-shirt. ■...

I need help with the following question on Resolution in FOL. The custom officials searched everyone who entered this country who was not a VIP. Some of the drug pushers entered this country and they were only searched by drug pushers. No drug pushers was a VIP. Let E(x) mean ”x entered...

Homework Statement is there any intuition of why the center of mass formula is what it is? in high school the teacher says is is what it is and that's that or something like that but is there any logic behind it? Homework Equations The Attempt at a Solution

I recently learned predicate calculus from Schaum's Outline of Logic. in this sort of form: In addition to refutation trees, however; pfff, refutation trees. I'm reading "Introduction to Set Theory," Hrbacek, Jech. I'm a little "annoyed" by the informal proofs. [FONT="Arial Black"]Are any...

If two numbers are not equal, there is infinitely many numbers between them. Therefore, numbers that are equal have a finite amount of numbers between them, 0. Therefore, numbers with a finite amount of numbers between them are equal.

Homework Statement So I have four bits input(X0,X1,X2,X3), and I need to check if these four bits are monotonic sequence. I got the following function: Y0 = X2X1X0 + X3'X2'X1' + X3'X2'X0 (Y0 - the output 1 when X0>=X1>=X2>=X3) Y1 = X2'X1'X0' + X3X1'X0' + X3X2X1' (Y1 - The output 1...

Were computers or any such devises there during George Boole's times who lived through 1815-1864? I don't think there were any such things, then what did motivate or make Boole to invent such a new field? Please help me with this. Thanks.