explanation of Slur #'details?

[Marc Hohl]

Hello,

is there a description of Slur #'details? I googled for some of the 
parameters and did a git grep, but I didn't find
anything which would explain the meaning of these parameters:

((region-size . 4) (head-encompass-penalty . 1000.0) 
(stem-encompass-penalty . 30.0) (closeness-factor . 10) 
(edge-attraction-factor . 4) (same-slope-penalty . 20) 
(steeper-slope-factor . 50) (non-horizontal-penalty . 15) (max-slope . 
1.1) (max-slope-factor . 10) (free-head-distance . 0.3) 
(free-slur-distance . 0.8) (extra-object-collision-penalty . 50) 
(accidental-collision . 3) (extra-encompass-free-distance . 0.3) 
(extra-encompass-collision-distance . 0.8) (head-slur-distance-max-ratio 
. 3) (head-slur-distance-factor . 10) (absolute-closeness-measure . 0.3) 
(edge-slope-exponent . 1.7))

Marc