CSC165&Lecture&Notes& && & &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&Created&by:&Lavender&Y.&
th
[Jan%20 ]%Lecture%07%Disjunction%&%Negation%
%
Review:%
All)employee)make)under)75,000)and)over)100,000)
Predicate:)
u(x):& “employee&x&makes&under&75,000”&
o(x):& “employee&x&makes&over&100,000”&
!!!!!!!!!!!!!!!!!!!!!!!!!!∀!! ∈ !,[! ! ∧ !(!)]&
• Truth&values&P,Q&
(! ∧ !))is)true)if)and)only)if)both)P,)Q)are)true.)(false)otherwise))
&
P% Q% P%=>%Q%
T% T& T&
T% F& F&
F% T& T&
F% F& T&
&
Employee% Gender% % Salary%
A1% Male& 60,000&
Betty% Female& &&& 500&
Carlos% Male& 40,000&
Doug% Male& 30,000&
Ellen% Female& 50,000&
Flo% Female& 20,000&
&
7.1%Disjunction%
& The&employee&is&female&or&earns&more&than&35,000&
& e.g.&True&for&Flo,&Carlos,&Ellen&
& e.g.&False&for&Doug&
&
Predicates:&
& !(x):& “employee&x&is&female”&
& R(x):& “employee&makes&more&than&35,000”&
! ! ∨ !(!)&
• ! ∨ !& is&true&if&and&only&if&at&least&one&of&P,Q&are&true&
• inclusive&or&BBB&True&when&both&properties&true&
• English:&you&may&take&CSC148&or&SC150&for&credit&(exclusive,¬&both)&
B ! ∧ ¬! ∨ (¬! ∧ !)& &
B &
Quantification,& Implication,& Conjunction& and& Disjunc&ion& give& ways& to& restrict& domains& under&
consideration.& & & CSC165&Lecture&Notes& && & &&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&& &&&&&&&&&&&&&&& Created&by:&Lavender&Y.&
• Every&D&that&is&a&P&is&also&a&Q& & ∀!! ∈ !,[! ! => !(!)]&
&
D&
&
& & & & && P&& & & Q&
& & & & (empty)&
&
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