Scans characters backward from POS till it finds\n\
a change in the PROP property, then returns the position of the change.\n\
The optional third argument OBJECT is the string or buffer to scan.\n\
-The property values are compared with `eq'.
+The property values are compared with `eq'.\n\
Return nil if the property is constant all the way to the start of OBJECT.\n\
If the value is non-nil, it is a position less than POS, never equal.")
(pos, prop, object)