Using the chain rule for any of the likelihoods, *free* or *clamped*,

Differentiating eqns.1.39 and 1.40 wrt
, to get two results for *free* and *clamped* cases and
using the common result in eqn.1.25, we get substitutions for
both terms on the right hand side of eqn. 1.41. This substitution
yields two separate results for *free* and *clamped* cases.

where is a Kronecker delta.

Substitution of eqns. 1.42 and 1.43 in the eqn.1.38(keeping in mind that in this case) gives the required result,

Fri May 10 20:35:10 MET DST 1996