Finally cut out and removed a tree root that was an obstruction to lawn mowing. It cost me a reciprocating saw blade because of the rock that turned out to be behind it, but I finally go the thing out. The tree is a volunteer and I hope the wind blows it down anyway. It'll be easier to cut up if that happens. I should have cut it down when I could have used a pocketknife. There's one more root to take out on it and then I'll be done with it. But I have to go slow on these things because of my sore back.