[GRASS-user] compute path with a maximum slope

[lists at lazygranch.com]

I have a DEM in grass using a proj that is in UTM. Viewshed, slope, etc
work fine. What I want to do is have grass compute a path between two
points such that the slope doesn't exceed a maximum value. I don't care
about the path length. 

I suspect there is some guide on the internet for this problem, but
just can't compose the right question for a search engine. A link would
be appreciated. If not, some basic guidance would be helpful.