The package provides four primary commands for vertically scaling and
stretching objects, and a number of derivative commands.  Its primary
function is the ability to scale/stretch and shift one object to conform
to the vertical size of a specified second object. This feature can be
useful in both equations and schematic diagrams.

Additionally, the scaling and stretching commands offer constraints on
maximum width and/or minimum aspect ratio, which are often used to
preserve legibility or for the sake of general appearance.

