1. How would you classify the following statement? $$ x \vee \neg x $$ Contradiction
    Contingence
    Tautology
    Does not parse
    I don't know yet
    What is your answer?

  2. How would you classify the following statement? $$ x \wedge \neg x $$ Contradiction
    Contingence
    Tautology
    Does not parse
    I don't know yet
    What is your answer?

  3. How would you classify the following statement? $$ x \vee y $$ Contradiction
    Contingence
    Tautology
    Does not parse
    I don't know yet
    What is your answer?

  4. How would you classify the following statement? $$ x \land y \lnot \lnot $$ Contradiction
    Contingence
    Tautology
    Does not parse
    I don't know yet
    What is your answer?

  5. How would you classify the following statement? $$ \lnot \lnot z \lor a $$ Contradiction
    Contingence
    Tautology
    Does not parse
    I don't know yet
    What is your answer?

  6. How would you classify the following statement? $$ x \lnot \land y $$ Contradiction
    Contingence
    Tautology
    Does not parse
    I don't know yet
    What is your answer?

  7. How would you classify the following statement? $$ (x \wedge y) \land (z \wedge \neg y) $$ Contradiction
    Contingence
    Tautology
    Does not parse
    I don't know yet
    What is your answer?

  8. How would you classify the following statement? $$ x \leftrightarrow (x \vee y) $$ Contradiction
    Contingence
    Tautology
    Does not parse
    I don't know yet
    What is your answer?

  9. How would you classify the following statement? $$ (a \wedge b) \leftrightarrow (b \land a) $$ Contradiction
    Contingence
    Tautology
    Does not parse
    I don't know yet
    What is your answer?

  10. How would you classify the following statement? $$ \left(z \wedge \left(z \rightarrow y\right)\right) \rightarrow \neg y $$ Contradiction
    Contingence
    Tautology
    Does not parse
    I don't know yet
    What is your answer?