I am reading the book Elements of the Representation Theory of Associative Algebras: Volume 1, by Assem, Simson and Skowroński. I have a question on page 290, line 19, how to show that
$$\operatorname{Hom}_A\left(\tau^{-1}(\bigoplus\limits_{k=1}^i P(k))\oplus(\bigoplus\limits_{l=i+1}^n P(k)), M\r...
Please don't create a tag when there's an equivalent one. I don't know if your question will remain closed (people can vote reopening), so please don't create a redundant tag. Maintaining the tags somewhat coherent is a lot of work, and distinct equivalent tags is an issue. — YCor8 hours ago
Ex Falso Quodbilet or the Principle of Explosion is that from a false/contradiction we can derive any proposition; that is $\bot \vdash A$.
Dually, do we have from any proposition we can derive truth, that is $A \vdash \top$? If so does it have name?
I am reading the book "Elements of the representation theory of associative algebras", Volume 1, by Assem, Simson and Skowroński. I have a question on Lemma 5.8, page 290, line 19, how to show that
$$\operatorname{Hom}_A\left(\tau^{-1}(\bigoplus\limits_{k=1}^i P(k))\oplus(\bigoplus\limits_{l=i+1}...
Ex Falso Quodbilet or the Principle of Explosion is that from a false/contradiction we can derive any proposition; that is $\bot \vdash A$.
Dually, do we have from any proposition we can derive truth, that is $A \vdash \top$? If so does it have name?
