This may be nit-picky, but I noticed inconsistencies in a high school math text I was reading, and I'm curious what the world thinks.
For the most part throughout this textbook, notation is used as such:
The notation $\overline{AB}$ is used to refer to the line that contains both points A and B.
The notation $\overrightarrow{AB}$ is used to refer to the directed line segment that begins at A and ends at B. (I have also seen this used to refer to the ray that begins at A and passes through B.)
My question arises in the context of rigid transformations in the Euclidian plane:
$T_\overrightarrow{AB}(P)$ where $P$ is a figure in the plane.
This asks us to translate $P$ by the directed line segment $\overrightarrow{AB}$.
In some places in this textbook, however, this translation is written as $T_\overline{AB}(P)$.
This seems questionable: how can you translate a figure along a line without orientation or endpoints? Are we supposed to assume that the order of the letters describes the orientation? (actually, there's no question we're supposed to assume this...but should we?)
Am I being nit-picky or is this reasonable?