Esther Rantzen Esther Rantzen Dame Esther Louise Rantzen (born 22 June 1940) is an English journalist and television presenter, who presented the BBC television series "That's Life!" for 21 years, from 1973 until 1994. She works with various charitable causes, and founded the charities ChildLine, promoting child protection, which she set up in 1986, and The Silver Line, designed to combat loneliness, which she set up in 2012. Rantzen was born in Berkhamsted, Hertfordshire, England, to Katherine Flora Rantzen ("née" Leverson, 1911–2005) and Henry Barnato Rantzen (1902–1992). She has one younger sister, Priscilla N. Taylor. She attended Buckley Country Day School in
Well-founded semantics assigning propositions "true" or "false", it also allows for a value representing ignorance. For example, if we know that codice_1 but we do not know whether or not specimen "A" flies during the day, the well-founded semantics would assign the proposition ``specimen A is a moth`` the value "bottom" which is neither "true" nor "false". The well-founded semantics is also a way of making safe inferences in the presence of contradictory data such as noisy data, or data acquired from different experts who may posit differing opinions. Many two-valued semantics simply won't consider such a problem state workable. The well-founded