A four-dimensional and nonlinear example about a mixing-tank-system from a paper by O. Stursberg, S. Kowalewski and S. Engell [10].

The two differential equations (V'1,V'2)=(0.008,0.015) do not influence the example. They are kept in order to test how algorithms handle such irrelevant inputs.

Initially, V1(0)=1, V2(0)=1, and (h(0),c(0)) in [1.32,1.5]×[1.2,1.32], where h is liquid height and c is concentration. We want to verify that the state {(V1,V2,h,c):h in [1.1,1.3] /\c in [1.68,1.80] } is unreachable.

Input file