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Yes, it is certainly a proof (in a most commonly-used logic systems) There may be some logic systems where proof by contradiction is not a proof. The existence
by theamk 8y ago
Yes, it is certainly a proof (in a most commonly-used logic systems)
There may be some logic systems where proof by contradiction is not a proof. The existence of such logic systems does not mean there is any disagreement between mathematicians.
- foldr 8y agoNo, it doesn't, but as a matter of fact there has been disagreement among mathematicians on those issues. See e.g. https://en.wikipedia.org/wiki/Brouwer%E2%80%93Hilbert_controversy https://en.wikipedia.org/wiki/Brouwer%E2%80%93Hilbert_contro....