What do we do when there are two conditional indicators? For example:
No student is chosen for Gryffindor unless they exhibit bravery. Therefore, if a student exhibits bravery, they will be sorted to Gryffindor. Lawgic:
A → B
B → A
The argument is invalid.
How come it is not /chosen->/exhibit bravery? indicator “no” and indicator “unless” make negate sufficient condition and negate necessary condition. If we create the contrapositive it makes brave-> chosen which matches the second sentence.