geom:difference

(geom:difference a b &key color label)

A new solid: a with b removed -- a plate with a bolt hole, a block with a slot milled in it. The operands are taken in world coordinates and left untouched; the result is a new root solid, with (geom:history result) answering (:difference a b). A hole exactly as deep as the plate is thick goes all the way through: coplanar faces are a handled case, not a corner one. See the solid modeling guide.