**Written work, **Due Tuesday, October 23, in class:

Chapter 4 p.100: 4, 5, 10, 11

Chapter 5 p.110: 1, 4, 9

*Odd problems are worth 4 points, even problems worth 8 points.
*

**WeBWorK**– none

**OpenLab**– none

Skip to the content

**Written work, **Due Tuesday, October 23, in class:

Chapter 4 p.100: 4, 5, 10, 11

Chapter 5 p.110: 1, 4, 9

*Odd problems are worth 4 points, even problems worth 8 points.
*

- OpenLab #1: Advice from the Past – 2019 Fall – MAT 2071 Proofs and Logic – Reitz on OpenLab #7: Advice for the Future
- Franklin Ajisogun on OpenLab #7: Advice for the Future
- Franklin Ajisogun on OpenLab #3: “Sentences”
- Franklin Ajisogun on OpenLab #6: Proof Journal
- Jessie Coriolan on OpenLab #7: Advice for the Future

- Are complete and totally proper forcing the same? November 9, 2024See this question for the definition of totally proper forcing, which is confusingly called strongly proper in Cummings' handbook chapter (which clashes with the more recent notion of strong properness due to Mitchell). There is also the notion of complete forcing invented by Shelah; see for example Definition 2.2.1 of On subcomplete forcings by Minden. […]new account
- Is this theory a conservative extension of Heyting Arithmetic ($\sf HA$)? November 9, 2024Consider the following theory over some axiomatixation of first-order $\sf S4$ modal logic with equality: Universal generalizations of: $\neg s(x)=0$ $s(x)=s(y) \to x=y$ $x+0=x$ $x+s(y)=s(x+y)$ $x \times 0=0$ $x \times s(y)=(x \times y)+x$ $\Box (A(0) \land \forall y (A(y) \to A(s(y)))) \to A(x)$ Further, this theory is closed under Necessitation: From $\vdash A$, infer $\vdash […]PW_246
- Recursive Function to Count Sub-Expressions in Boolean Expressions November 9, 2024I'm working on a logic assignment and need some help defining a recursive function, countexprs. This function should, given a Boolean expression, return the total count of all sub-expressions within the expression. The expressions are defined by the following grammar: BExpr ::= bool | (BExpr ∧ BExpr) | (BExpr ∨ BExpr) | (¬BExpr) According to […]asfasfasf
- On a natural deduction rule concerning $\exists$ elimination [duplicate] November 9, 2024I wanted to see how a natural deduction proof system works, so I started reading these notes. On page four we find the following rule: $$\frac{ \begin{matrix} & & \left[\phi[t/v]\right]\\ & & \vdots\\ \exists v\phi & & \psi \end{matrix}} {\psi}$$ provided the constant $t$ does not occur in $∃vφ$, or in $ψ$, or in any […]Sam
- Why is propositional logic not incomplete? [duplicate] November 9, 2024I am struggling to understand the basics of logic. I don't understand the following. I know that in propositional logic the statement "A and (not B)" is true under certain interpretations of the symbols and false under others. It is also unprovable since it is not a tautology. This seems to me to be analogous […]Adam
- Help with trying to formally proof FOL $\exists x \forall y (Rxy \to Fa) \vdash \exists x \forall y Rxy \to Fa$ November 9, 2024There does not seem to exist a counter-model which makes the premise true and the conclusion false, but I can't work out a formal deduction for $\exists x \forall y(Rxy \to Fa) \vdash \exists x \forall y Rxy \to Fa$. Any help is appreciated!useruser334455
- Help With FOL Natural Deduction Proof ∀x∀y(R(x,y) ∨ x=y), ∀x∃y¬x=y ⊢ ∀y∃x(¬x=y ∧ R(x,y)) [closed] November 9, 2024So far, I only got the reversed universal and existential quantifiers. I can't use CQ rules or anything. Please helpWayfaring Stranger
- How was logical implication invented ? Trouble understanding it intuitively. November 9, 2024I'm a bit perplexed by implication as I can't make sense of it in any empirical manner. Could someone please indicate how it was invented or derived. I believe getting the intuition for implication in a derived sense will make sense to me rather then trying to justify it's existence by stating things like "a […]ImpliedCurious
- Confusion about claim on truth functions (Elliot Mendelson, Introduction to Mathematical Logic) November 8, 2024A truth function of $n$-arguments is defined to be a function of $n$- arguments, the arguments and values of which are the truth values T or F. As we have seen, any statement form containing n distinct statement letters determines a corresponding truth function of n arguments. He then futher elaborates, To be precise, enumerate […]Francis Augustus
- Natural Numbers under Sum Constraints November 8, 2024PROBLEM: Each natural number is coloured blue or red, so if $x$ and $y$ are painted the same colour, then $x+y$ is painted blue (note that it could be $x=y$). Determine all the ways to colour the natural numbers that follow this rule. MY WORK: I thought about what happens if I choose a particular […]Alejandro Lorite

"Math Improve"
.999
1
assignment
assignments
calculus
calendar
Doodling
exam #3
exam 3 grades
final papers
grading criteria
grading policy
graph theory
group paper
group project
homework
logic
mathography
metacognition
only if
openlab
OpenLab #4: Bridges and Walking Tours
OpenLab7
OpenLab 8
OpenLab8
Open Lab 8
openlab assignment
perfect circle
points
presentation
project
resource
rubric
semester project
spring classes
vi hart
ViHart
visual math
Wau
webwork
week 8
week 14
welcome
written work

© 2024 2018 Fall – MAT 2071 Proofs and Logic – Reitz

Theme by Anders Noren — Up ↑

Our goal is to make the OpenLab accessible for all users.

top

Our goal is to make the OpenLab accessible for all users.

## Leave a Reply