1. Law of Detachment:


Laws of logic
 


Law of Detachment:



Law of Detachment:
 Premise: If I play baseball, then I need a glove.    p ® q
 Premise: I play baseball          p  
 Conclusion:               \
 
 
Law of Contrapositive: p ® q
          \
 
Law of Modus Tollens: p ® q
          ~ q    
           \
 
Chain Rule:
 Premise: If today is Monday, then I go to school.    p ® q
 Premise: If I go to school, then I have homework.    q ® r
 Conclusion:               \
 
 
Law of Disjunctive Inference:
 Premise: Mrs. Ryan has coffee or tea at every meal.    p v q
 Premise: Mrs. Ryan does not have coffee at dinner.    ~ q  
 Conclusion:               \
 
 
Law of Double Negation: ~ (~p) =
 
 
DeMorgan’s Laws:  ~ (p v q) =
     ~ (p Ù q) =
 
 
 
Law of Simplification: p Ù q or p Ù q
            \ p         \ q
 
Law of Conjunction:   p
           q  
            \ p Ù q
 
Law of Disjunctive Addition:
 p  
  \ p v q

Back to top