A sketch: pen commands on a placement, or loops, several closed outlines making one face, the
first its outside and each further one a hole in it, such as a washer or a plate with cut-outs. An
outline is closed when it ends with close or back at its start; a closed outline is made a face
unless face is false, and an open one stays a wire. Each command's id, distinct across the
sketch's loops, names the sides a later feature sweeps from it.
A sketch: pen commands on a placement, or
loops, several closed outlines making one face, the first its outside and each further one a hole in it, such as a washer or a plate with cut-outs. An outline is closed when it ends withcloseor back at its start; a closed outline is made a face unlessfaceis false, and an open one stays a wire. Each command'sid, distinct across the sketch's loops, names the sides a later feature sweeps from it.