I can't find the proof of this corollary: if $R$ is a PID, then every finitely generated projective $R$-module is free.
Please help me.
I can't find the proof of this corollary: if $R$ is a PID, then every finitely generated projective $R$-module is free.
Please help me.
A finitely generated projective $R$-module is a direct summand of a finitely generated free module. Furthermore, a submodule of a finitely generated free module over a P.I.D. is free.