The implication operator
⇒ is often difficult to manipulate directly. We utilize the fundamental identity:
X⇒Y≡(∼X)∨Y
By substituting
X=(p∨q) and
Y=((∼r)∨p), we transform the statement into:
S≡∼(p∨q)∨((∼r)∨p)
Next, we address the term
∼(p∨q). According to
De Morgan's Law, the negation of a disjunction is the conjunction of the negations:
∼(p∨q)≡(∼p)∧(∼q)
Substituting this back into our expression for
S, we obtain:
S≡((∼p)∧(∼q))∨((∼r)∨p)
To simplify further, we use the
Associative Law to group the terms containing
p:
S≡(((∼p)∧(∼q))∨p)∨(∼r)
Since
(∼p)∨p is a
Tautology (
T), and
T∧X≡X, the expression simplifies significantly:
S≡(p∨(∼q))∨(∼r)
S≡p∨(∼q)∨(∼r)
The problem requires the
negation of
S, denoted as
∼S. We apply the negation operator to our simplified expression:
∼S≡∼(p∨(∼q)∨(∼r))
Applying
De Morgan's Law across the three terms, we flip the OR operators to AND operators:
∼S≡(∼p)∧(∼(∼q))∧(∼(∼r))
Using the
Double Negation Law, where
∼(∼X)≡X, we arrive at the final result:
∼S≡(∼p)∧q∧r
This result corresponds to the logical structure presented in Option (C). By methodically deconstructing the operators, we have reduced a complex implication to its simplest conjunctive form.