“In one of Lal’s earlier posts, I think it was mentioned that tanha arises from asavas and that avijja and asavas strengthen each other.”
Is it this post: “Gathi (Gati), Anusaya, and Āsava”
I put in “asava tanha” in the “Search box” and this is one of the posts that came up.
Tanha and avijja go together. Both grow together and are eliminated together at the Arahant stage.
They are related to lobha and moha respectively. The other root cause dosa is a manifestation of lobha. So, when lobha and moha (or tanha and avijja) are eliminated all three root causes are eliminated.
P.S. Siebe just sent me a reference sutta that explains this:
“34. Causes (AN 3.34)”
Thank you, Siebe!