Effective quantifier elimination procedures for the reals allow to solve pr
oblems that can be encoded into corresponding first-order formulas includin
g ordering constraints. In contrast to constraint logic programming, which
is often used in similar areas, this encoding is straightforward, A quantif
ier elimination procedure using test point ideas is part of the package RED
LOG by the author ct al. REDLOG is part of REDUCE 3.7. We discuss how this
method can be used for analysis, sizing, and error diagnosis of physical ne
tworks. The focus is on electrical networks.