Why is Modus Ponens a valid arguement form?
118480
Is modus ponens a tautology?
47222
Soundness of a rule of a proof system with respect to the truth tables?
136577
In formal logic, how is it possible for an argument with a contradictory conclusion to be valid?
6938
"I believe it's valid" vs. "I believe it valid"
12143
argumental reference inconsistency in javascript
95851
Validity of an argument with a contradictory conclusion
51863
Logical Conditional Truth Table Rationale
15504
In classical logic, why is $(p\Rightarrow q)$ True if $p$ is False and $q$ is True?
89435
Word or idiom for someone holding (seemingly) contradictory views
35370
Why is this proposition provable and its converse not?
88188
Explain proof by contradiction.
46924
Why do people who subscribe to self-refuting skeptical philosophies still argue with others?
111797
Without computers, how can you conjecture the (in)validity of a long convoluted argument in Predicate Logic?
101738
When is absence of evidence not evidence of absence?
147051
Soundness vs completeness, am I understanding? And proving soundness?
109685
An invalid argument, the conclusion of which is a tautology
103342
Why should we care about syntactic proofs if we can show semantically that statements are true?