I've considered studying in my office before but hesitated because I worried about drawing attention to myself. Did you deal with any awkward interactions from co-workers or supervisors who noticed you staying later to study? And if so, how?
... logical expression semantically entails certain valid conclusions. Short of proof -theoretic ... went about listing all the valid categorical syllogisms. They gave them ...
... ." This would NOT be a valid inference. On the other hand ... ." This would actually be a valid inference. The fact that the ... or not it becomes a valid inference dictates that they are ...