# lecture3 - CS245 Winter 2010 Lecture 3 Shai Ben-David The...

This preview shows pages 1–2. Sign up to view the full content.

CS245 - Winter 2010, Lecture 3 Shai Ben-David The language of propositional Calculus We no turn back to our main theme of developing formal languages for the analysis of logical implications (as well as other logical notions). The first step in the construction of a formal language is defining the set of expressions of that languages. These play a role similar to that played by words, or sentences, in natural languages. The expressions of the language of Propositional Calculus are called Proposi- tional Formulas . We define the set of propositional formulas using the structural induction tool that we have just introduced. We start by defining the underlying domain set (the set X , in the discussion of definitions by structural induction above). Let Σ = { lower-case English letters with and without subscript indices }∪{→ , , , ¬ , ) , ( } Σ is the set of ”letters” of our language. For any give set Σ, the set of all finite sequences of member of Σ is denoted by Σ * . The domain set for the definition of propositions formulas is the set X = Σ * , where Σ is the set of characters defined above.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern