Necessary and sufficient conditions for estimability and regulability are derived for time variant and time invariant systems, in discrete and continuous time.

The reasoning usually goes along the lines: ' Talk shows, which started out innocently, have degenerated into ambush television'.

[…]to Anne Mercer, my daughter, the some of xiiij li., according to an agrement between her husband and me, to be paid within one fortnith of the death of my wiffe.

Although more than two decades have passed, not a day goes by that I don't wonder how things could and should be different for the many children like Lydia who fall through the cracks because they are misdiagnosed, mistreated, or simply misunderstood.