contrapositive,then you can do this sincethe statementand its contrapositiveare equivalent.
Example 1
If then. True.
Statement:If , then. False.
Converse:A counterexampleis, where but is not
Inverse: If is not then is not. False.A counterexampleiswhere is not but =
Contrapositive: If is not , then is not. True.If is not , then and is notExample 2
If then is the midpointof. False(as shownbelow).
Statement:NeedsConverse: If is the midpointof , then. True.If , then is not the midpointof. True.
Inverse:If is not the midpointof , then False(see the diagramabove).
Contrapositive:BiconditionalStatements
You recallthat the converseof “If then ” is “If then .” Whenthesetwo are combined,we havea
biconditionalstatement.
Biconditional: and
In symbols,this is writtenas: