Ditto 1980's era Australian physics and engineering courses.
Throw in a right hand thumbs up for "direction" of curl (fingers indicate rotation, orthogonal thumb direction is orientation) and other results about paths having to have a zero rotation between places with opposing rotation, etc.
Throw in a right hand thumbs up for "direction" of curl (fingers indicate rotation, orthogonal thumb direction is orientation) and other results about paths having to have a zero rotation between places with opposing rotation, etc.