Invalid parameter values will return an error detailing which parameter is problematic.
Details
The Loglogistic distribution with shape parameter \(\tau\) and scale parameter
\(\lambda\) has density:
$$\frac{\tau \lambda^\tau x^{\tau -1}}{(\lambda^{\tau }+x^{\tau })^{2}}$$
for \(x \in \mathcal{R}^+\), \(\lambda, \tau > 0\).