Recent content by kp100591

can you suggest a one-element model for W1 please ?

Consider the following well-formed formulae in the Predicate Calculus: W1 = (∃x)(∃y) R(x, y) W2 = (∀x)(∀y) [R(x, y) ⇒ ∼ R(y, x)] W3 = (∀x)(∀y) [R(x, y) ⇒ (∃z)(R(z, x) ∧ R(y, z))] Prove that any model in which W1, W2 and W3 are all true must have at least 3 elements. Find one such model with 3...

hello, i was wondering if anyone could help me with this induction proof. thank you A positive well-formed formula in the Propositional Calculus is a well-formed formula that avoids all use of the negation symbol ∼ . (a) Use induction on the length of a wff to prove that if W = W(P1,...,Pn) is...