propositional and predicate logic Flashcards
logic
the study of reasoning; rational ways of drawing conclusions
proposition
claim about how things are; either true or false but not both
represented by letters
atomic propositions
where the truth or falsity of this proposition doesn’t depend on the truth or falsity of another proposition
compound propositons
a proposition created by combining atomic propositions through fundamental connectives
what are the 6 fundamental connectives
and
or
xor
not
conditional/implication
biconditional
∧
and; forms a third proposition from two other propositions called a conjunction
conjunction is true when both initial propositions are true
∨
or; forms a third proposition from two other propositions called a disjunction
disjunction is true when at least one of the other propositions are true
⊕
xor; forms a third proposition called an exclusive disjunction which is true when only one of the propositions are true
¬ ~
not; forms a second proposition called a negation which is the opposite of the propostion
→
what are the 2 parts
what makes them true
conditional; if.. then
has an antecedent (if) and a consequent (then)
if a is true then c is true
if both are false then the implication is true
if only the consequent is false then the implication is true
↔
biconditonal; if and only if
combines two propositions into a biconditional which is true if both propositions have the same truth value
what are the 4 types of logical properties
tautologies
contradictions
contingencies
equivalents
tautologies
propositions that are always true regardless of their atomic propostions
contradictions
propositions that are always false
contingencies
propositions that are neither tautologies or contradictions