Paul Crowley comments on Bizarre Illusions

[Paul Crowley]

I’m not sure that the idea of orthogonality is defined for modules, is it? Is there a standard definition of an inner product for a Z-module?

[komponisto]

I’m not sure that the idea of orthogonality is defined for modules, is it? Is there a standard definition of an inner product for a Z-module?

Yes; the same definition works. See here.

[Zack_M_Davis]

Yay! I actually got something right!