![Ideals and Reality: Projective Modules and Number of Generators of Ideals (Springer Monographs in Mathematics) : Ischebeck, Friedrich, Rao, Ravi A.: Amazon.de: Books Ideals and Reality: Projective Modules and Number of Generators of Ideals (Springer Monographs in Mathematics) : Ischebeck, Friedrich, Rao, Ravi A.: Amazon.de: Books](https://m.media-amazon.com/images/I/61FHnJ5fFZL.jpg)
Ideals and Reality: Projective Modules and Number of Generators of Ideals (Springer Monographs in Mathematics) : Ischebeck, Friedrich, Rao, Ravi A.: Amazon.de: Books
![File:Diagram used in the proof of the free summand characterisation of projective modules.svg - Wikimedia Commons File:Diagram used in the proof of the free summand characterisation of projective modules.svg - Wikimedia Commons](https://upload.wikimedia.org/wikipedia/commons/thumb/1/1f/Diagram_used_in_the_proof_of_the_free_summand_characterisation_of_projective_modules.svg/2458px-Diagram_used_in_the_proof_of_the_free_summand_characterisation_of_projective_modules.svg.png)
File:Diagram used in the proof of the free summand characterisation of projective modules.svg - Wikimedia Commons
![abstract algebra - If $F$ is free, then the functor $M \mapsto \operatorname{Hom}_A(F,M)$ is exact. - Mathematics Stack Exchange abstract algebra - If $F$ is free, then the functor $M \mapsto \operatorname{Hom}_A(F,M)$ is exact. - Mathematics Stack Exchange](https://i.stack.imgur.com/GNTkD.png)
abstract algebra - If $F$ is free, then the functor $M \mapsto \operatorname{Hom}_A(F,M)$ is exact. - Mathematics Stack Exchange
![Commutative Algebra/Torsion-free, flat, projective and free modules - Wikibooks, open books for an open world Commutative Algebra/Torsion-free, flat, projective and free modules - Wikibooks, open books for an open world](https://upload.wikimedia.org/wikipedia/commons/thumb/c/c0/Projective-proof3.svg/400px-Projective-proof3.svg.png)