[BUG] ISO 13-11

[Tevian Dray]

I finally tracked down a copy of ISO 13-11 -- thanks to Oregon State
University for ordering a copy.  Here are the most important items:

11-12.3: Spherical coordinates are (r,theta,phi), with theta from the
         North Pole, and phi in the equatorial plane.

11-12.2: Cylindrical coordinates are (rho,phi,z), with phi as above.

These are followed by figures which also define the adapted unit vectors
geometrically, in the notation e_r, etc.  

Apart from the use of rho for the cylindrical radial coordinate, these
are precisely the "physics" conventions used in the Bridge Project.
Both standards also contain expressions for the position vector and its
differential.  For what it's worth, both theta and phi are written in
their "script" form, although I doubt that means much.

Other relevant items:

11-7.12: Uses parentheses to evaluate derivatives in Leibniz notation,
         as in ( df/dx )_{x=a}.

(The use of a vertical bar for evaluation appears only in the context of
evaluating integrals, with both an upper and lower limit.)

11-7.18: Suggests by omission that surface and volume integrals should
         be written with a single integral sign.

11-9.8:  States strongly that "arcsin" should always be used rather than
         "sin^{-1}" (with similar comments for other inverse trig fns).
         
11-12.1: The standard coordinate system is "cartesian" rather than
         either "Cartesian" or "rectangular".

11-13.1: States that arrows can be used to denote vectors "instead" of
         boldface.  (I personally prefer using both.)

11-13.4: Allows either i,j,k or e_x,e_y,e_z for rectangular unit
         vectors.  (Hats do not appear at all.)

Tevian