square([abs(ab[0]), abs(ab[1])]);
}
module circleat(c,r) { translate(c) circle(r); }
+module linextr(z0,z1) {
+ translate([0,0,z0])
+ linear_extrude(height=z1-z0)
+ children();
+}
module KeeperProfile(slant=0){
use_e = kppe + [0,-1] * slant * keeper_inner_width / keeper_slant_slope;