Our aim is to present sufficient conditions ensuring Hoffman's error bound
for lower semicontinuous nonconvex inequality systems and to analyze its im
pact on the local controllability, implicit function theorem for (non-Lipsc
hitz) multivalued mappings, generalized equations (variational inequalities
), and sensitivity analysis and on other problems like Lipschitzian propert
ies of polyhedral multivalued mappings as well as weak sharp minima or line
ar conditioning. We show how the information about our sufficient condition
s can be used to provide a computable constant such that Hoffman's error bo
und holds. We also show that this error bound is nothing but the classical
Farkas lemma for linear inequality systems. In the latter case our constant
may be computed explicitly.