LPL 3.4 EC

# LPL 3.4 EC - LPL 3.4 EXTRA CREDIT RIK SENGUPTA NOTE...

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

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.

Unformatted text preview: LPL 3.4 EXTRA CREDIT RIK SENGUPTA NOTE: Throughout this proof we define “A is equivalent to B” as “the truth value of A is the truth value of B”. Let P be a true sentence and let Q be formed by putting some number of negation symbols in front of P. Case 1: Q is formed by putting an even number 2n of negation symbols in front of P. We want to prove that Q is true. Let R(n) be the statement “If Q is formed by putting 2n (where n is an integer) negation symbols in front of a true statement P, then Q is true”. Obviously, R(0) is true, as then Q ≡ P, and P is true, so obviously Q is also true (from Identity Elimination). Also, R(1) is true, because “P is true” implies “the negation of P is false” implies “the negation of the negation of P is true”, because the negation of the negation of P is equivalent to P itself. Let R(i) be true for some integer i. We want to show that R(i + 1) is also true. But, proving R(i + 1) is true is equivalent to proving that the negation of the negation of the Q that appeared in R(i) is true (because...
View Full Document

{[ snackBarMessage ]}

### Page1 / 2

LPL 3.4 EC - LPL 3.4 EXTRA CREDIT RIK SENGUPTA NOTE...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online