if have, let´s say, an rectangle and a circle above it, is there a way to
"melt" the cross-points, so after that i can do some fillet at the remaining form?
Trying to do the fillet right after drawing will result in loss of the rest of existing line,
for exmp. at the rectangle. Also trying to go for trimming does not help, as there is
always a loss of line-segments i still want to keep.