Assertion: isometry | /r/HasProperty | combined with k -fold rotational isometries
Facets:
value: about the same axis
type: OTHER
Source sentences:
text: all isometries which are a combination of a rotation about some axis and a proportional translation along the axis; in general this is combined with k -fold rotational isometries about the same axis ( k ≥ 1 ); the set of images of a point under the isometries is a k -fold helix; in addition there may be a 2-fold rotation about a perpendicularly intersecting axis, and hence a k -fold helix of such axes.