Abstract
Persistent bifurcation diagrams in unfoldings of the modal
family $g(x,\lambda)=\varepsilon
x^{4}+2ax^{2}\lambda+\delta\lambda^{2}$ are described using path
formulation: each bifurcation problem in the unfoldings of
g is reinterpreted as a $\lambda$-parametrized path in
the universal unfolding of $x^{4}$. The space of
unfolding parameters for the modal family is divided into
regions where bifurcation problems are contact-equivalent and
the bifurcation diagrams for these persistent problems are
shown.