Tautology, Satisfiable, Logical Truth

Let S be a sentence of FOL built up using truth functional connectives

• S is a tautology if and only if every row assigns T to S.
• S is satisfiable if and only if there is at least one non-spurious row of the truth table that assigns T to S.
• S is logically true if and only if every non-spurious row assigns T to S.

 
• Exercises