The values for the propositional variables p, q, s, are determined as follows: p = true q = false s = true Determine the truth values for the following propositions (show your work) a. p or (q rightarrow s) b. (s harr q) or (p and q) Give truth tables for the following propositions. Use the guidelines from last assignment (1.1 - 1.2) for your truth table (e.g., canonical order for the rows: columns for all subexpressions). a. (p rightarrow q) or (r and q) b. (p or p) + q Show whether the following logical expressions are tautologies, contradictions or neither. A compound proposition that is neither a tautology nor a contradiction is called a contingency. You can approach this problem using a truth table or making an argument (see zyBook Section 1.4 on Logical equivalence.) a. (p or q) or (q rightarrow p)