(X⇒Y)⇒((Z⇒Y)⇒(Z⇒X))

asked by guest
on Oct 22, 2024 at 12:08 pm



MathBot Answer:

Logic Expression
Symbol: $\left(X \rightarrow Y\right) \rightarrow \left(\left(Z \rightarrow Y\right) \rightarrow \left(Z \rightarrow X\right)\right)$
Text: $\left(X \text{ implies } Y\right) \text{ implies } \left(\left(Z \text{ implies } Y\right) \text{ implies } \left(Z \text{ implies } X\right)\right)$


Classification contingency


Truth Table

Legend

$X$$Y$$Z$$X \rightarrow Y$$Z \rightarrow Y$$Z \rightarrow X$$\left(Z \rightarrow Y\right) \rightarrow \left(Z \rightarrow X\right)$$\left(X \rightarrow Y\right) \rightarrow \left(\left(Z \rightarrow Y\right) \rightarrow \left(Z \rightarrow X\right)\right)$
11111111
11011111
10100111
10001111
01111000
01011111
00110011
00011111
T/F

Simplification$$\begin{gathered} \left(X \rightarrow Y\right) \rightarrow \left(\left(Z \rightarrow Y\right) \rightarrow \left(Z \rightarrow X\right)\right) & \equiv & \left(\neg X \vee Y\right) \rightarrow \left(\left(Z \rightarrow Y\right) \rightarrow \left(Z \rightarrow X\right)\right) & \text{Conditional Equivalence} \\ & \equiv & \left(\neg X \vee Y\right) \rightarrow \left(\left(\neg Z \vee Y\right) \rightarrow \left(Z \rightarrow X\right)\right) & \text{Conditional Equivalence} \\ & \equiv & \left(\neg X \vee Y\right) \rightarrow \left(\left(\neg Z \vee Y\right) \rightarrow \left(\neg Z \vee X\right)\right) & \text{Conditional Equivalence} \\ & \equiv & \left(\neg X \vee Y\right) \rightarrow \left(\neg \left(\neg Z \vee Y\right) \vee \neg Z \vee X\right) & \text{Conditional Equivalence} \\ & \equiv & \left(\neg X \vee Y\right) \rightarrow \left(\left(\neg \left(\neg Z\right) \wedge \neg Y\right) \vee \neg Z \vee X\right) & \text{De Morgan's Law} \\ & \equiv & \left(\neg X \vee Y\right) \rightarrow \left(\left(Z \wedge \neg Y\right) \vee \neg Z \vee X\right) & \text{Double Negation Law} \\ & \equiv & \left(\neg X \vee Y\right) \rightarrow \left(\neg Y \vee \neg Z \vee X\right) & \text{Redundancy Law (2)} \\ & \equiv & \neg \left(\neg X \vee Y\right) \vee \neg Y \vee \neg Z \vee X & \text{Conditional Equivalence} \\ & \equiv & \left(\neg \left(\neg X\right) \wedge \neg Y\right) \vee \neg Y \vee \neg Z \vee X & \text{De Morgan's Law} \\ & \equiv & \left(X \wedge \neg Y\right) \vee \neg Y \vee \neg Z \vee X & \text{Double Negation Law} \\ & \equiv & \neg Y \vee \neg Z \vee X & \text{Absorption Law} \end{gathered}$$ Note: Solution may not be as simplified as possible.


Conjunctive Normal Form$$\neg Y \vee \neg Z \vee X$$


Note 1: These equivalences and tautologies are used to generate the above steps.
Note 2: Two logical statements are logically equivalent if they always produce the same truth value. Consequently, p ≡ q is same as saying p ↔ q is a tautology. $$\begin{array}{c|c}\textbf{Equivalence} \\ \hline \text{Absorption Law} & \begin{gathered} p \wedge \left(p \vee q\right) \equiv p \\ p \vee \left(p \wedge q\right) \equiv p \end{gathered} \\ \hline \text{Biconditional Equivalence} & \begin{gathered} p \leftrightarrow q \equiv \left(p \vee \neg q\right) \wedge \left(\neg p \vee q\right) \\ p \leftrightarrow q \equiv \left(p \wedge q\right) \vee \left(\neg p \wedge \neg q\right) \end{gathered} \\ \hline \text{Biconditional Simplification} & \begin{gathered} p \leftrightarrow p \equiv \text{True} & p \leftrightarrow \text{True} \equiv p \\ p \leftrightarrow \neg p \equiv \text{False} & p \leftrightarrow \text{False} \equiv \neg p \end{gathered} \\ \hline \text{Complement Law} & \begin{gathered} p \wedge \neg p \equiv \text{False} \\ p \vee \neg p \equiv \text{True} \end{gathered} \\ \hline \text{Conditional Equivalence} & p \rightarrow q \equiv \neg p \vee q \\ \hline \text{Conditional Simplification} & \begin{gathered} p \rightarrow p \equiv \text{True} & p \rightarrow \text{True} \equiv \text{True} & p \rightarrow \text{False} \equiv \neg p \\ p \rightarrow \neg p \equiv \neg p & \text{True} \rightarrow p \equiv p & \text{False} \rightarrow p \equiv \text{True} \\ \neg p \rightarrow p \equiv p\end{gathered} \\ \hline \text{Consensus Law} & \begin{gathered} \left(p \vee q\right) \wedge \left(\neg p \vee r\right) \wedge \left(q \vee r\right) \equiv \left(p \vee q\right) \wedge \left(\neg p \vee r\right) \\ \left(p \wedge q\right) \vee \left(\neg p \wedge r\right) \vee \left(q \wedge r\right) \equiv \left(p \wedge q\right) \vee \left(\neg p \wedge r\right) \end{gathered} \\ \hline \text{De Morgan's Law} & \begin{gathered} \neg \left(p \wedge q\right) \equiv \neg p \vee \neg q \\ \neg \left(p \vee q\right) \equiv \neg p \wedge \neg q \end{gathered} \\ \hline \text{Distributive Law} & \begin{gathered} p \wedge \left(q \vee r\right) \equiv \left(p \wedge q\right) \vee \left(p \wedge r\right) \\ p \vee \left(q \wedge r\right) \equiv \left(p \vee q\right) \wedge \left(p \vee r\right) \\ \left(p \vee q\right) \wedge \left(r \vee s\right) \equiv \left(p \wedge r\right) \vee \left(p \wedge s\right) \vee \left(q \wedge r\right) \vee \left(q \wedge s\right) \\ \left(p \wedge q\right) \vee \left(r \wedge s\right) \equiv \left(p \vee r\right) \wedge \left(p \vee s\right) \wedge \left(q \vee r\right) \wedge \left(q \vee s\right) \end{gathered} \\ \hline \text{Domination Law} & \begin{gathered} p \vee \text{True} \equiv \text{True} \\ p \wedge \text{False} \equiv \text{False} \end{gathered} \\ \hline \text{Double Negation Law} & \neg \left(\neg p\right) \equiv p \\ \hline \text{Idempotent Law} & \begin{gathered} p \wedge p \equiv p \\ p \vee p \equiv p \end{gathered} \\ \hline \text{Identity Law} & \begin{gathered} p \wedge \text{True} \equiv p \\ p \vee \text{False} \equiv p \end{gathered} \\ \hline \text{NAND} & p \uparrow q \equiv \neg \left(p \wedge q\right) \\ \hline \text{Negation Law} & \begin{gathered} \neg \text{True} \equiv \text{False} \\ \neg \text{False} \equiv \text{True} \end{gathered} \\ \hline \text{NOR} & p \downarrow q \equiv \neg \left(p \vee q\right) \\ \hline \text{Negation of Biconditional Equivalence} & \begin{gathered} \neg \left(p \leftrightarrow q\right) \equiv \left(p \vee q\right) \wedge \left(\neg p \vee \neg q\right) \\ \neg \left(p \leftrightarrow q\right) \equiv \left(p \wedge \neg q\right) \vee \left(\neg p \wedge q\right) \end{gathered} \\ \hline \text{Negation of Conditional Equivalence} & \neg \left(p \rightarrow q\right) \equiv p \wedge \neg q \\ \hline \text{Redundancy Law (1)} & \begin{gathered} \left(p \vee q\right) \wedge \left(p \vee \neg q\right) \equiv p \\ \left(p \wedge q\right) \vee \left(p \wedge \neg q\right) \equiv p \end{gathered} \\ \hline \text{Redundancy Law (2)} & \begin{gathered} p \wedge \left(\neg p \vee q\right) \equiv p \wedge q \\ p \vee \left(\neg p \wedge q\right) \equiv p \vee q \end{gathered} \\ \hline \text{XOR} & \begin{gathered} p \oplus q \equiv \left(p \vee q\right) \wedge \left(\neg p \vee \neg q\right) \\ p \oplus q \equiv \left(p \wedge \neg q\right) \vee \left(\neg p \wedge q\right) \end{gathered} \\ \hline \text{XOR Simplification} & \begin{gathered} p \oplus p \equiv \text{False} & p \oplus \text{True} \equiv \neg p \\ p \oplus \neg p \equiv \text{True} & p \oplus \text{False} \equiv p \end{gathered} \\ \hline \text{XNOR} & p \odot q \equiv \neg \left(p \oplus q\right) \end{array}$$ $$\begin{array}{c|c}\textbf{Tautology} \\ \hline \text{Conjunctive Simplification} & \begin{gathered} \left(p \wedge q\right) \rightarrow p \\ \left(p \wedge q\right) \rightarrow q \end{gathered} \\ \hline \text{Contradiction} & \neg \left(p \wedge \neg p\right) \\ \hline \text{Contrapositive} & \left(p \rightarrow q\right) \leftrightarrow \left(\neg q \rightarrow \neg p\right) \\ \hline \text{Disjunctive Addition} & \begin{gathered} p \rightarrow \left(p \vee q\right) \\ q \rightarrow \left(p \vee q\right) \end{gathered} \\ \hline \text{Disjunctive Syllogism} & \begin{gathered} \left(\left(p \vee q\right) \wedge \neg q\right) \rightarrow p \\ \left(\left(p \vee q\right) \wedge \neg p\right) \rightarrow q \end{gathered} \\ \hline \text{Hypothetical Syllogism} & \left(\left(p \rightarrow q\right) \wedge \left(q \rightarrow r\right)\right) \rightarrow \left(p \rightarrow r\right) \\ \hline \text{Modus Ponens} & \left(p \wedge \left(p \rightarrow q\right)\right) \rightarrow q \\ \hline \text{Modus Tollens} & \left(\neg q \wedge \left(p \rightarrow q\right)\right) \rightarrow \neg p \end{array}$$