Midterm 2 Definitions Flashcards
When is a (particular) argument Deductively Valid?
If and only if it is an instance of a valid form.
When is an argument FORM Deductively Valid?
If and only if there are no instances of that form in which all the premises are true and the conclusion false, aka it has no counterexample.
When is a sentence a Compound Sentence?
If and only if it logically contains another complete sentence (simple sentence) as a component.
When is a sentence a Simple Sentence?
If and only if it is not a compound sentence.
What is a Sentential Operator?
An expression containing blanks such that, when the blanks are filled with complete sentences, the result is a complete sentence.
When is a sentential operator Truth-Functional?
If and only if the truth or falsity of a compound sentence containing that operator is completely determined by the truth or falsity of its component sentences.
What is a Counterexample to an argument form?
An instance of that form where all the premises are true and the conclusion false.
When is a statement form a Tautology?
If and only if every instance of that form is true; that is, it is true in every row in its truth table.
When is a statement form a Contradiction (or inconsistent)?
If and only if every instance of that form is false; that is, it is false in every row in its truth table.
When is a statement form a Contigency?
If and only if some instance of that form is true and some is false; that is, it is true in at least one row in its truth table and false in at least one row in its truth table.
Fill in the blank: Deductive Validity of an argument depends on its ____.
Form.
What is the study of argument forms called?
Formal Logic.
What is an Instance of a form?
When a form’s variables (ex: “p” and “q” in “p->q”) are replaced with sentences (ex: “cold” and “windy” in “if cold then windy”).
Is the following sentence compound or simple: Jason Bay hit 3 homers and struck out.
Compound. Can be deconstructed as “JB hit 3 homers and JB struck out.” – still logically means the same thing though.
Fill in the blanks: Compound sentences are built from _____ sentences by means of ______.
Component, sentential operators.
True or False: Component sentences are simple sentences.
True.
Name four common sentential operators.
“Either – or –.”
“– and –.”
“If –, then –.”
“— if and only if —“
True or False: There are an infinite number of sentential operators in the English language.
True.
Fill in the blank: If you want to know whether a (compound) sentence is true or not, determine the truth or falsity of the ___ sentences.
Component.
Name the five Truth-Functional Sentential Operators.
Conjunction, disjunction, negation, conditional, and biconditional.
What are a conjunction’s component sentences are called?
Conjuncts.
What is an ampersand and what is it used for?
“And” or “&”
Used for conjunctions.
What are a disjunction’s component sentences are called?
Disjuncts.
What is the TFSO in this sentence: (B&F).
“&” or “and”
This is a conjunction.
What is a wedge and what is it used for?
“Either, or” or “v”
This is a disjunction.
What is the TFSO in this sentence:
(LvF).
“v” or “either, or”
This is a disjunction.
What are a negation’s component sentences called?
Negated formulas.
What is a tilde and what is it used for?
“Not” or “it is not the case that” or “~”
It is used for negations.
What is the TFSO in this sentence: ~W.
”~” or “not” or “it is not the case that”
This is a negation.
What are a conditional’s component sentences called?
First component sentence is called the Antecedent. Second component sentence is called the Consequent.
What is the only TFSO where order matters?
Conditional.
What is an arrow and what is it used for?
“If, then” or “->”
Used for conditionals.
What is the TFSO in this sentence: (T->S).
”->” or “if, then”
This is a conditional.
Which goes first, “if” or “then”?
If, always.
True or False: Consequent arrow Antecedent.
False, it is Antecedent arrow Consequent.
What is a double arrow and what is it used for?
”<->” or “if and only if”
Used for biconditionals.
What is the TFSO in this sentence: (R<->A).
”<->” or “if and only if”
This is a biconditional.
Translate this sentence: The would be WET if i had STIRRED it.
(S -> W). “If” goes first always.