Universal & Existential quantification.md (505B)
1 +++ 2 title = 'Universal & Existential quantification' 3 +++ 4 # Universal & Existential quantification 5 ## Universal 6 ∀x ϕ — for all values of x, ϕ is true 7 8 ∀x x — contradiction 9 10 in propositional logic: 11 12 ∀x ϕ ≡ ϕ1 ∧ ϕ0 13 14 ## Existential 15 ∃x ϕ — there exists a value of x where ϕ is true 16 17 ∃x x — tautology 18 19 in propositional logic: 20 21 ∃x ϕ ≡ ϕ1 ∨ ϕ0 22 23 Build OBDDs using the propositional logic versions. Compute the variables and then take conjunction (∀) or disjunction (∃).