system3={{x31,x32,x33,x34,x35,x36},{u31,u32,u11,u12,y21,wg1,wg2,wg3,wg4,wg5,wg6},{y31,y32,z31,z32},{{1+θb31,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,1+θb33},{1+θb31,-1+θb32,0,1,0,0,0,0,0,0,0,0,0,0,0,0,1+θb34},{1-θb32,-1+θb31,0,0,1,0,1+θb33,1+θb34,0,0,1+θb31,0,0,0,0,0,1+θb31},{1+θb33,1+θb34,0,0,0,1,-1-θb34,1+θb33,0,0,-1-θb32,0,0,0,0,0,-1-θb32},{1-θb34,0,0,0,-1,1,0,0,1+θb33,0,1+θb34,0,0,0,0,0,1-θb34},{0,-1+θb33,0,0,-1,-1,0,0,0,1+θb34,0,0,0,0,0,0,-1+θb33},{1,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0},{0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0},{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},{0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}},{1,2},{1,2},{1,2},{3,4,5,6,7,8,9,10,11},{1,2},{3,4}}/.{θb311,θb321/2,θb333/2,θb341};systemcheck[system3]