Find Consistency Of System Specifications1. p ∧ ¬ q = T2. ( q ∧ p...
veirarer
Answered
2022-06-26
Find Consistency Of System Specifications 1. 2. 3. 4. From Eq 1, we got and . Now Apply value of P in Eq 3, we get:
Now there are two possibilities when is T, and is F but the r has two separate values.
Answer & Explanation
lorienoldf7
Expert
2022-06-27Added 19 answers
Step 1 A set of sentences as consistent iff their conjunction is satisfiable. (Informally: a consistent system is one whose premises/axioms are coherent in some universe.) So, in propositional logic, an inconsistent system is one whose conjunction is a contradiction, i.e., whose conjunction is false regardless of the combination of truth values of its atomic propositions. So, in your exercise, the system is inconsistent iff , i.e., regardless of (p, q, r)'s value, 's truth table has a False main connective. Because the main connective in your simplified truth table of is True thrice, your system is consistent.
Roland Manning
Expert
2022-06-28Added 5 answers
Step 1 It's perfectly ok that your set of sentences is consistent if you have 2 different models satisfying your set of sentences (a theory) since consistency has nothing to do with uniqueness of model as referenced here a consistent theory is one that does not lead to a logical contradiction. The lack of contradiction can be defined in either semantic or syntactic terms. The semantic definition states that a theory is consistent if it has a model, i.e., there exists an interpretation under which all formulas in the theory are true. Step 2 In fact any set of tautological sentences such as can always have different truth values for any propositional sentence p, q, r to stay to be consistent. But look further about your set of particular sentences, r can only be true from the constraint of your last sentence 4 since the antecedent of your material conditional is true then r has to be true...