Exercise 1: Deriving the Denial Condition for Admin ^ (Owner v SharedWith) — Possible Solution ==================================================================== THE STARTING EXPRESSION ------------------------------ The access rule is: Admin ^ (Owner v SharedWith) Its negation - the denial condition - is: ~(Admin ^ (Owner v SharedWith)) STEP 1: APPLYING DE MORGAN'S LAW FOR AND ------------------------------ Per Chapter 2's own De Morgan's Law, ~(p ^ q) = ~p v ~q. Treating p = Admin and q = (Owner v SharedWith): ~(Admin ^ (Owner v SharedWith)) = ~Admin v ~(Owner v SharedWith) STEP 2: APPLYING DE MORGAN'S LAW FOR OR TO THE REMAINING TERM ------------------------------ The inner term ~(Owner v SharedWith) is itself a negated OR. Per Chapter 2's own De Morgan's Law for OR, ~(p v q) = ~p ^ ~q. Treating p = Owner and q = SharedWith: ~(Owner v SharedWith) = ~Owner ^ ~SharedWith STEP 3: SUBSTITUTING BACK IN ------------------------------ Combining both steps: ~Admin v (~Owner ^ ~SharedWith) THE FINAL DENIAL CONDITION ------------------------------ ~Admin v (~Owner ^ ~SharedWith) In plain English: access is denied when the user is not an admin, OR (they don't own the resource AND it wasn't shared with them). This reads naturally as the correct denial message: "you're not an admin, and you neither own this resource nor was it shared with you." WHY BOTH DE MORGAN'S LAWS WERE NEEDED, NOT JUST ONE ------------------------------ The original expression has two nested connectives - an outer AND and an inner OR - so negating it fully requires applying De Morgan's Law twice: once to flip the outer AND into an OR (per Chapter 2's rule for AND), and again to flip the newly-exposed inner OR into an AND (per Chapter 2's rule for OR). Stopping after only the first application would have left ~(Owner v SharedWith) unsimplified, still containing a negated compound expression rather than a fully distributed one. WHY THIS WORKS AS AN ANSWER ------------------------------ It applies De Morgan's Law in two separate, clearly labeled steps - first to the outer AND, then to the newly-exposed inner OR - arriving at a fully simplified denial condition with no remaining negated compound expressions, and translates the result into a natural plain-English denial message.