| OCR Text |
Show 26 x*? is son of Billf -x will contain: ('John/', 'Eric') x^John is son of ? -x will contain ('Bill') x+7 is ? of Bill -x will contain ((•son», "John"), ('son', 'Eric')) The e operation yields a logical result. The possible associative operators follow. form j^eanong x is y of z creates and stores the relationship x isn y of z destroys the relationship if it exists xey of z asks if relationship is true xjty of z asks if relationship is false - in general we ask for x R y of ? all z having relation y with x x R ? of z all relationship between x and z x R ? jpf ? all relations that x is involved in ? R y of_ z all values with relation y with z ? R y of ? all pairs having relation y ? R ? of z all relations and values that z is involved in Concatenation # is the concatenation operator. The result is the concatenation of the two operands. The topology of the result is the most general topology of the two operands. |
