Zulip Chat Archive

Stream: Is there code for X?

Topic: Transform connected component into subgraph


Lessness (Oct 26 2023 at 20:12):

Hi!
I have C: G.ConnectedComponent and want to say that it is equal to some given M: G.Subgraph, after transforming C into G.Subgraph. Is it possible using Mathlib?

(If I'm unclear, apologies. Foggy brain etc.)

Kyle Miller (Oct 26 2023 at 20:16):

I thought we had function somewhere for transforming a connected component into a subgraph, but it's not so bad to do directly. I haven't tested this, but I believe it's

( : G.Subgraph).induce C.supp = M

Lessness (Oct 26 2023 at 20:27):

What is T in this case? (Still a noob, not understanding things sometime.)

Yaël Dillies (Oct 26 2023 at 20:30):

It's the complete graph.

Lessness (Oct 26 2023 at 20:32):

Oh... so it's not letter T (t).

Thank you

Kyle Miller (Oct 26 2023 at 20:40):

It's pronounced "top" for "top of the lattice of subgraphs of G". There's also , pronounced "bot" for "bottom", which would be the empty subgraph of G in this context.

Kyle Miller (Oct 26 2023 at 20:40):

Yaël Dillies said:

It's the complete graph.

It's G as a subgraph of itself to be more accurate


Last updated: Dec 20 2023 at 11:08 UTC