* \n If φ is an atomic formula (sentential letter) of sentential logic, then φ is true on σ∗ just in case σ assigns the value T to φ, and false otherwise.
* If φ is a formula of the form ¬ψ, then φ is true on σ∗ just in case ψ is false on σ∗, and false otherwise.
* If φ is a formula of the form (ψ&ρ), then φ is true on σ∗ just in case both ψ and ρ are true on σ∗, and false otherwise.
* If φ is a formula of the form (ψ∨ρ), then φ is true on σ∗ just in case either ψ is true on σ∗ or ρ is true on σ∗, and false otherwise.
* If φ is a formula of the form (ψ→ρ), then φ is true on σ∗ just in case either ψ is false on σ∗ or ρ is true on σ∗, and false otherwise.