The validity of an inference depends on the form of the inference. That is, the word valid does not refer to the truth of the premises or the conclusion, but rather to the form of the inference. An inference can be valid even if the parts are false, and can be invalid even if some parts are true.
LONDON -- President Barack Obama and wife Michelle Obama were welcomed to Buckingham Palace in grand royal style Tuesday by Queen Elizabeth II as they began their official state visit to Britain, a rare honor for a U.S. president.bama's mission, in part, is to reassure Britain and the rest of Europe that the traditional U.S. allies still have a central role in a U.S. foreign policy that has become increasingly focused on Asia and other emerging markets.
12.27 While we're waiting for President Obama and Mr Cameron to finish their burgers and put their aprons in the laundry, here's the picture desk's slideshow of  US President Barack Obama's state visit to Britain: day two in pictures .hanks for following the live events of day two of Barack Obama's visit to Britain. 20.59 Tonight's guests at the state banquet will also enjoy some entertainment. American Tony Award winning singer and actress Kristin Chenoweth will perform after the dinner.