Manuel Bodirsky Peter Jonsson Timo von Oertzen Semilinear Program Feasibility. 79-90 2009 ICALP (2) http://dx.doi.org/10.1007/978-3-642-02930-1_7 conf/icalp/2009-2 db/conf/icalp/icalp2009-2.html#BodirskyJO09