observable part
slo = obsvss(sl) [Ao, Bo, Co] = obsvss(A, B, C) .. = obsvss(.., tol)
real matrices
syslin lists
real (threshold) (default value 100*%eps)
slo=(Ao,Bo,Co) is the observable part of linear system sl=(A,B,C) (syslin list)
tol threshold to test controllability (see contr);
default value = 100*%eps