The basic object type in this program is a vector: a linear combination of the three unit vectors el, e2, e3 that form an orthonormal right-handed basis. A vector takes the form: al*e(1) +a2*e(2) +a3*e(3) where the aj, j E {I, 2, 3} are scalar expressions. The unit vectors e(j) are defined by means of an operator, e, which is declared noncommutative for reasons that will be explained soon: operator e; noncom e; Extracting a cartesian co-ordinate out of a vector can be done using camp: procedure comp (j, u); df (u, e (j)) ; Next to addition and scalar multiplication, the ...
