Geometry (Logic)
posted by Lisa on .
Which argument is not valid?
1.) Given: a→b
a
Conclusion: b
2.) Given: a˅b
~b
Conclusion: ~a
3.) Given: a→b
~b
Conclusion: ~a
4.) Given: a→b
b→~c
Conclusion: a→~c

#2 is not an argument, since there is no implication.