Olympic Games Australia and Europe). The coloured version of the rings—blue, yellow, black, green, and red—over a white field forms the Olympic flag. These colours were chosen because every nation had at least one of them on its national flag. The flag was adopted in 1914 but flown for the first time only at the 1920 Summer Olympics in Antwerp, Belgium. It has since been hoisted during each celebration of the Games. The Olympic motto, "Citius, Altius, Fortius", a Latin expression meaning "Faster, Higher, Stronger" was proposed by Pierre de Coubertin in 1894 and has been official since 1924. The motto was
Higher-order logic "classical" higher-order logic. However, modal higher-order logic has been studied as well. According to several logicians, Gödel's ontological proof is best studied (from a technical perspective) in such a context. Higher-order logic In mathematics and logic, a higher-order logic is a form of predicate logic that is distinguished from first-order logic by additional quantifiers and, sometimes, stronger semantics. Higher-order logics with their standard semantics are more expressive, but their model-theoretic properties are less well-behaved than those of first-order logic. The term "higher-order logic", abbreviated as HOL, is commonly used to mean higher-order simple predicate logic. Here "simple" indicates that the