An interpretation or valuation is a function that assigns a truth-value to every propositional symbol $P$, hence $v(P) \in \{ 0, 1 \}$.
- If , then is true under the interpretation .
- If , then is false under the interpretation . An interpretation is extended to all well-formed formula using truth-tables.
As oppossed to FC1, we include an extra column for for interpretation. For example, take , we generate the following truth table:
| interpretation | |||
|---|---|---|---|
| F | F | F | |
| F | T | F | |
| T | F | F | |
| T | T | T |