Table of logical values
 
 
 
Simple statements compound statements sets of statements arguments
true logically true (tautologies): 
All rows have T's
logically equivalent: 
statements have identical truth values 
valid: 
No row with T's in premises and F in conclusion
false logically false (contradictions): 
All rows have F's
logically consistent: 
At least one row in which all statements have T's
Invalid: 
At least a row with T's in premises and F in conclusion
logically contingent: 
Some rows have T's, some have F's
logically inconsistent: 
No row in which all statements have T's