stacksemantics

43 ms·

1. 1.▲
   by stacksemantics 6y ago

   Constructive mathematicians do not assert that excluded middle is true since there is no constructive proof of (P not P). Nor do they assert that it is false, since that statement, (not (P or not P)), is constructively refutable i.e. there
2. 2.▲
   by stacksemantics 6y ago

   There is only one kind of proof by contradiction. Assume not P, derive a contradiction which implies not not P, then conclude (via excluded middle) P. If you assume P, derive a contradiction, then conclude not P, that is a direct proof of n
3. 3.▲
   by stacksemantics 6y ago

   Constructive mathematics does not affirm excluded middle. That's distinct from rejecting it.