Block option to model

I have a question about the block option for the model.How do I write the model so that I can use a “block” option?

What you you mean? You don’t need to modify your model. See e.g.

Thank you, professor.
I now have this problem: Could not normalize the model. Variable k is not in the maximum cardinality matching.
But I want to know what block decomposition is first, I feel I know nothing about this, can you recommend some materials to learn related content?

See e.g.
Could you maybe provide the mod-file?