Thanks for the post Edgar.  I have reported the bug to the powers that be...

Tim

this help page can be read. I think that it is not available in Mac, so here it is:

theta function,
n. any of a class of special functions that are important in topology, number theory, and analysis. The basic such function from which all others can be derived is the entire function

theta[3](z,q) = 1 + 2*sum((q^(n^2))*cos(2*nz), n=1..infinity)

where q = e^(piit) for im t > 0. When analytic properties are concerned, the dependence on q is suppressed. The special theta function

theta[3](q) = theta[3](0,q) = 1 + 2*sum((q^(n^2)), n=1..infinity)

is the generating function of the sequence of square numbers. It satisfies the remarkable theta transformation formula:

sqrt(s) theta[3][exp(-pis)] = theta[3][exp(-pi/s)].

Compare triple product identity.