Translating Sentences into Quantified Propositions: Practice Problems

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SUMMARY

This discussion focuses on translating sentences into quantified propositions using logical notation. The participants analyze five specific examples, including statements about engineers, mathematicians, writers, athletes, and scientists. Each proposition is expressed with defined functions and domains, such as E(x) for engineers and C(x) for being good with computers. The discussion confirms that the use of parentheses in logical expressions is not strictly enforced in the course material.

PREREQUISITES
  • Understanding of first-order logic and quantified statements
  • Familiarity with propositional functions and logical notation
  • Basic knowledge of mathematical logic terminology
  • Ability to define domains for logical variables
NEXT STEPS
  • Study the principles of first-order logic in detail
  • Learn about the use of quantifiers in mathematical logic
  • Explore common logical notation and its conventions
  • Practice translating complex sentences into quantified propositions
USEFUL FOR

Students of logic, mathematics, and philosophy, as well as educators teaching formal logic and its applications in reasoning.

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Homework Statement



I've been trying to translate the following sentences into quantified propositions by making sure I state all propositional functions that I use and any assumptions that I make.

Can you see if I'm on the right track here?

Homework Equations

The Attempt at a Solution



1. All engineers are good with computers.

Let ##E(x)## be '##x## is an engineer' and ##C(x)## be '##x## is good with computers,'
where the domain of ##x## is all people in the world.

Then, ##\forall x\ E(x) \rightarrow C(x)##.2. Some mathematicians also like poetry.

Let ##M(x)## be '##x## is a mathematician' and ##P(x)## be '##x## also likes poetry,'
where the domain of ##x## is all people in the world.

Then, ##\exists x\ M(x) \land P(x)##.

3. There are no writers who do not like reading books.

Let ##W(x)## be '##x## is a writer' and ##B(x)## be '##x## likes reading books,'
where the domain of '##x## is all people in the world.

Then, ##\neg\ \exists x\ W(x) \land \neg B(x)##.

4. Not every athlete is famous.

Let ##A(x)## be '##x## is an athlete' and ##F(x)## be '##x## is famous,'
where the domain of ##x## is all people in the world.

Then, ##\neg \forall x\ A(x) \rightarrow F(x)##.

5. Only scientists properly value civilisation.

Let ##S(x)## be '##x## is a scientist' and ##C(x)## be '##x## properly values civilisation,'
where the domain of ##x## is all people in the world.

Then, ##\forall x\ C(x) \rightarrow S(x)##.
 
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failexam said:
Can you see if I'm on the right track here?

You are on the right track. Is your course material particular about using parentheses and brackets?

For example,

##\neg \forall x\ A(x) \rightarrow F(x)##.

could be written as:

##\neg (\forall x (\ A(x) \rightarrow F(x)) )##
 
No it's not very picky about the parenthesis.

Thanks, though!
 

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