> I am using 5.9.3 to solve for the constants of a differential equation.
> In doing so, I was dealt a new label which I've not seen before. The
> output contains %r1 which could more clearly be represented by its value
I think you need to include the initial condition z(L/2)=0 in the
arguments to algsys:
consts:algsys([bc1,bc2,bc3,bc4,bc5,bc6,bc7,bc8,z(L/2)=0],
[C1,C2,C3,C4,C5,C6,C7,C8]);
This seems to give the answer you expected.
Algsys uses %r1 to represent a parameter ranging over the reals, e.g.:
algsys([x=1],[x,y]) => [[x = 1,y = %r6]]
algsys([x^2+y^2=1],[x,y]) =>
[[x = %r10,y = sqrt(1-%r10^2)],[x = %r11,y = -sqrt(1-%r11^2)]]