"Truth tables with conjunctions, disjunctions, and conditional statements"

Logic Truth Tables

  • Truth Tables: Used to determine the truth value of logical expressions involving conjunctions, disjunctions, and conditional statements.
Key Definitions
  • Conjunction (): A logical connective where the compound statement is true if and only if both statements are true.
    • Notation: pextandqp ext{ and } q or p  q
  • Disjunction (): A logical connective where the compound statement is true if at least one statement is true.
    • Notation: pextorqp ext{ or } q or p  q
  • Conditional Statement: A statement of the form "if p, then q" denoted as p<br/>ightarrowqp <br /> ightarrow q. This statement is false only when p is true and q is false.
  • Negation (): The logical operation that inverts the truth value of a statement. If a statement is true, its negation is false.
    • Notation: extnotpext{not } p or <br/>egp<br /> eg p
Constructing a Truth Table
  1. Identify Variables: Determine the variables involved (e.g., p, q).
  2. List Possible Values: Create columns for each variable and their combinations of truth values (T for true, F for false).
  3. Calculate Derived Values: Based on logical operations (like conjunctions and conditionals), compute the resulting truth values in additional columns.
  4. Final Column: The last column in the truth table displays the resultant truth values for the derived expressions, corresponding to the initial variables.
Example Explanation
  • To complete the truth table for qightarrowpextandegqq ightarrow p ext{ and } eg q:
    • Start with the conditional q<br/>ightarrowpq <br /> ightarrow p:
    • This is only FALSE when qq is true and pp is false. Otherwise, it is TRUE.
    • Calculate <br/>egq<br /> eg q; when q is TRUE, <br/>egq<br /> eg q is FALSE, and vice versa.
    • The conjunction q
      ightarrow p 
      eg q will be TRUE only when both q<br/>ightarrowpq <br /> ightarrow p and <br/>egq<br /> eg q are TRUE.
Important Properties
  • Order of variables in conjunctions does not matter: p  q is equivalent to q  p.
  • Always emphasize the truth values in context to logical connectives to simplify evaluations in logic problems.
Remember
  • Use additional columns if necessary to clarify transitions through complex expressions.
  • Always focus on the final column which provides the answer to your logical evaluation.