Then you need to learn how. If not, then the same problems are still there. I'm not saying that the things you did were reasons that she had an A, but everyone could do with a little change to make themselves better.
"I've set boundaries and the consequences are I rage against her and humanity all in one breath."
That's not a consequence.
"Today they were in a meeting together and ow sat down RIGHT NEXT TO W." Does this sound like W has conveyed any NC at all? W called to tell me that, and I blew up and hung up."
Back it up. She called to tell you that the OW ended up sitting next to her. She didn't have to tell you. She could have just blown it off and not told you at all. But it sounded like out of respect for you, she told you and was honest about it. As long as the wasn't rubbing your face in it, then she was being transparent with you. You have to start seeing things like that.
These little steps are what leads to true reconciliation.
Now see it from her perspective. She told you the truth and then you punished her by blowing up at her. Do you think she'll want to tell you the next time something like that happens?
"And of course ow has no sense to stay the eff away. She took her place at W's side like she belongs there, and it is NOT ok with me."
So? You can't control what the OW is going to do. All you can do is control what your own actions are and trust your W to do the same.
"she says she didn't do anything wrong. ow sat down next to her."
And she's correct.
"W refuses to discuss what to do. For me, it's simple. You could say, that seat is taken. Simple."
That's YOUR response. You can't keep trying to control her.
"I know ow will continue to literally or figuratively take her place at W's side. Because she has to win. She has no moral fiber at all. She has dated 4 different people at our workplace and she just keeps getting away with all kinds of sh!t. And she's the head of HR, for god's sake!!!!! You'd think she might decide to keep her panties on with co-workers for that reason alone."
Again, you can't control what the OW does. You have to let that go.
"I'm so damn frustrated, I can't even begin to tell you..."
You need help to navigate through your emotions before you keep saying things that are going to hurt your sitch. Have the two of you been to counseling yet? You have to start letting go of your anger.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.