Predicate Logic Flashcards
label the constant and the predicate in this sentenc e
‘socrates is mortal’
how would you write this in predicate logic?
socrates - constant is mortal - predicate Socrates = s Is Mortal = M Ms
how do you say Socrates is not mortal in predicate logic
~Ms, when M - is mortal and s - Socrates
how do you say socrates is wiser than plato? with key please!
W…1…2 = 1 is wiser than 2
W- is wiser than
p- plato
s - socrates
Wps
how do you say manchester is between london and glasgow? key please!
B...1....2...3 = 1 is inbetween 2 and 3 B= is in between m - manchester l - london g - glasgow
Bmlg
when checking validity in a deductive argument with use of predicate logic, what are you looking for in the truth table?
check for instance of invalidity
e.g.
is there a row where the premise is true and the conclusion is false? IFF so, it is invalid.
how do you lay out the truth table for finding out if something is valid?
column per premise. e.g.
if you had
if dave goes to the party then angela won’t go
if angela goes to the party then vlad won’t go
vlad goes to the party
-
dave goes to the party
D… dave goes to the party
A… Angela goes to the party
V….. Vlad goes to the party
D ⊃~A A ⊃~V V - D
DAV | ~A | D ⊃~A | ~V | A ⊃~V | V | D|
——–| | | |
TTT F F F F F T
TTF F F T T T T
TFT T T F T F T
TFF T T T T T T
FTT F F F F F F
FTF F F T T T F
FFT T T F T F F < premises are
FFF T T T T T F true but conc
false - invalid
when translating english into predicate logic, what must we remember to do in regard with brackets?
add them to reveal the man operator - controlling the scope of the quantifiers
- don’t forget to also label the main operator
∀ - what symbol is this?
universal quantifier
means ‘all’
∃ - what symbol is this?
existential quantifier
means ‘some’ - some means - at least one in logic
∀, which constant do you typically use in these predicate translations?
⊃
∃, which constant do you typically use in these predicate translations?
^ ,∨
