Truth tables are a fundamental tool in [[Truth-Functional Logic]] (TFL) used to determine the truth value of complex sentences based on the truth values of their component [[Atomic Sentences]].
## Structure
- Rows: Each row represents a possible combination of truth values for the [[Atomic Sentences]].
- Columns: Each column shows the truth value of a subformula or the entire formula.
## Construction
1. List all [[Atomic Sentences]] and create columns for each.
2. Create rows for all possible combinations of truth values (T/F) for these atoms.
3. Add columns for each subformula, building up to the main connective.
4. Fill in truth values based on the definitions of the logical [[Connectives]].
## Uses
1. Determining [[Validity]]: An [[Argument]] is [[Valid]] if there's no row where all premises are true and the conclusion false.
2. Identifying [[Tautology|Tautologies]] and [[Contradiction|Contradictions]]
3. Checking for [[Logical Equivalence]]
4. Analyzing the truth-functional behavior of complex sentences
## Example
For p → (q ∨ r):
| p | q | r | q ∨ r | p → (q ∨ r) |
|---|---|---|-------|--------------|
| T | T | T | T | T |
| T | T | F | T | T |
| T | F | T | T | T |
| T | F | F | F | F |
| F | T | T | T | T |
| F | T | F | T | T |
| F | F | T | T | T |
| F | F | F | F | T |
Truth tables provide a systematic and exhaustive method for analyzing the logical properties of sentences in TFL, forming a cornerstone of truth-functional analysis.