An analysis of invariant curves (Q1123412)

The author uses the Lie derivative (without mentioning its name) to find the partial differential equation of representations of curves covariant in a given group of transformations and applies his result to plane euclidean geometry. [The work could be simplified considerably using known work of Lie and Tresse, part of which is exposed in the reviewer's book [Differential Geometry (1963; Zbl 0116.134)].]