What's the difference between a contrapositive statement and a contradiction?
17073
Using proof by contradiction vs proof of the contrapositive
23869
Prove the implication "if $ac>bc$ and $c>0$, then $a>b$" using the contrapositive
41318
Can every proof by contradiction also be shown without contradiction?
22193
Why, logically, is proof by contradiction valid?
85278
Should I use 'or' or 'nor' after a negative statement?
61303
"Infer" vs. "imply" — can "infer" imply "imply"?
129185
Understanding the truth value for ⇏ when antecedent is false and consequent is true.
52322
Implication in mathematics - How can A imply B when A is False?
125317
Is this statement "Every element in the empty set is greater than itself." true or its negation is true?
38031
What is a simple example of an unprovable statement?
102081
What is the difference between : and true?
113640
Why is there this strange contradiction between the language of logic and that of set theory?
15431
"A wrong answer" vs "the wrong answer"
74546
Negating A Mathematical Statement
147874
Why does the existence of independent statements not prove consistency?
39189
Argue by contradiction to show that there is no surjection...
37279
"can't" versus "couldn't", what is the difference?