  This paper can be an overview on solutions in Wronskian/Casoratian form to
soliton equations with KdV-type bilinear forms. We first investigate properties
of matrices commuting with a Jordan block, by which we derive explicit general
solutions to equations satisfied by Wronskian/Casoratian entry vectors, which
we call condition equations. These solutions are given according to the
coefficient matrix in the condition equations taking diagonal or Jordan block
form. Limit relations between these different solutions are described. We take
the KdV equation and the Toda lattice to serve as two examples for solutions in
Wronskian form and Casoratian form, respectively. We also discuss Wronskian
solutions for the KP equation. Finally, we formulate the Wronskian technique as
four steps.
