Summary of Equivalence Rules

 

  Double Negation

(DN)

p ≡ ~~p
 


  Contraposition

(CONTRA)

(p ⊃ q) ≡ (~q ⊃ ~p)
 

 

 

  Repetition

(REP)

p ≡ (p v p)
p ≡ (p & p)

 

  Commutation

(COM)

(p & q)  ≡ (q & p)
(p v q)  ≡ (q v p)

 

  DeMorgan

(DEM)

~(p v q) ≡ (~p & ~q)
~(p & q) ≡ (~p v ~q)

 

  Association

(ASSOC)

((p & q) & r) ≡ (p & (q & r))
((p v q) v r) ≡ (p v (q v r))

 

 

  Biconditional Exchange

(BE)

(p ≡ q)  ≡ [(p ⊃ q) & (q ⊃  p)]
 

 

  Conditional Exchange

(CE)

(p  ⊃  q)  ≡ (~p v q)
 

 

  Exportation

(EXPORT)

(p & q) ⊃ r)  ≡ ((p ⊃ (q  ⊃  r))
 

 

  Distribution

(DIST)

(p & (q v r)  ≡ (p & q) v (p & r)
(p v  (q & r)  ≡ (p v q) & (p v r)

 

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