Proving a negative
Encyclopedia
Proving a negative or negative proof may refer to:
- Evidence of absenceEvidence of absenceEvidence of absence is evidence of any kind that suggests the non-existence or non-presence of something. A simple example of evidence of absence: checking one's pocket for spare change and finding nothing but being confident that one would have found it if it were there...
in general, such as evidence that there is no milk in a certain bowl - Modus tollensModus tollensIn classical logic, modus tollens has the following argument form:- Formal notation :...
, a logical proof - Proof of impossibilityProof of impossibilityA proof of impossibility, sometimes called a negative proof or negative result, is a proof demonstrating that a particular problem cannot be solved, or cannot be solved in general. Often proofs of impossibility have put to rest decades or centuries of work attempting to find a solution...
, mathematics - Sometimes it is mistaken for an argument from ignoranceArgument from ignoranceArgument from ignorance, also known as argumentum ad ignorantiam or "appeal to ignorance" , is a fallacy in informal logic. It asserts that a proposition is true because it has not yet been proven false, it is "generally accepted"...
, which is non-proof and a logical fallacy.