  Given sets $\Phi_1=\{\phi_{11},...,\phi_{1u(1)}\},
...,\Phi_{z}=\{\phi_{z1},...,\phi_{zu(z)}\}$ of boolean formulas, a formula
$\omega$ follows from the conjunction $\bigwedge\Phi_i= \bigwedge \phi_{ij}$
iff $\neg \omega\wedge \bigwedge_{i=1}^z \Phi_i$ is unsatisfiable.
  Now assume that, given integers $0\leq e_i < u(i)$, we must check if $\neg
\omega\wedge \bigwedge_{i=1}^z \Phi'_i$ remains unsatisfiable, where
$\Phi'_i\subseteq \Phi_i$ is obtained by deleting $\,\,e_{i}$ arbitrarily
chosen formulas of $\Phi_i$, for each $i=1,...,z.$
  Intuitively, does $\omega$ {\it stably} follow, after removing $e_i$ random
formulas from each $\Phi_i$?
  We construct a quadratic reduction of this problem to the consequence problem
in infinite-valued \luk\ logic \L$_\infty$. In this way we obtain a
self-contained proof that the \L$_\infty$-consequence problem is coNP-complete.
