# So, math stuff. I like the “complete lattice”. I understand it. But I also like “constructive mathematics”. Intuitionistic logic. But without “law of excluded middle”, how do you get nice, clean separation between stuffs? Googling Constructive mathematics “complete lattice” and I get my next research: _Tarski’s lattice theoretical fixed point theorem_ which sounds really really familiar. I think I’ve been here before and here I am again.

So, math stuff.
I like the “complete lattice”. I understand it.
But I also like “constructive mathematics”. Intuitionistic logic.
But without “law of excluded middle”, how do you get nice, clean separation between stuffs?

Googling
Constructive mathematics “complete lattice”
and I get my next research:

_Tarski’s lattice theoretical fixed point theorem_

which sounds really really familiar. I think I’ve been here before and here I am again.
So, using my standard technique of:
a) Find influential paper
b) Go down a chain of popular citings until something sounds interesting.
c) Try to understand at least a piece of something that’s way over my head.
So, I ended up here. 260 pgs. I can’t read math symbols but sometimes I can gleam from text what something means.Introduction to Bisimulation and Coinduction
Davide Sangiorgi

Induction is a pervasive tool in computer science and mathematics for defining objects and reasoning on them. Coinduction is the dual of induction and as such it brings in quite different tools. Today, it is widely used in computer science, but also in other fields, including artificial intelligence, cognitive science, mathematics, modal logics, philosophy and physics. The best known instance of coinduction is bisimulation, mainly employed to define and prove equalities among potentially infinite objects: processes, streams, non-well-founded sets, etc. This book presents bisimulation and coinduction: the fundamental concepts and techniques and the duality with induction. Each chapter contains exercises and selected solutions, enabling students to connect theory with practice. A special emphasis is placed on bisimulation as a behavioural equivalence for processes. Thus the book serves as an introduction to models for expressing processes (such as process calculi) and to the associated techniques of operational and algebraic analysis.

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That’s what I like to do. Finding the right keywords can be tricky but once I ‘hit it’ it’s a really satisfying feeling reading somebody else working on the same problem I was thinking of.I’m often disappointed though. I’ll *think* I find “THE PAPER” or book and go through it, nodding “yes yes yes” but then there will be something that derails it where they go down the wrong path.

That’s a sinking feeling when that happens, but I’m still grateful that at least me and the paper author/s rode together for a ways at least.

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I read this comment _after_ I made my other comment – and watching a paper derail is different than us taking different forks down the same trail  In the case of a finding “the right paper”, matching up is key. But in our life paths / interest paths, forking is good.
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