我正在学习 Terry Halpin 的名为逻辑数据建模的教程(链接如下),但无法插入数据。 https://www.brcommunity.com/articles.php?id=b760
这是代码:
addblock 'Country(c), hasCountryCode(c:cc) -> string(cc).
Language(l), hasLanguageName(l:ln) -> string(ln).
isLarge(c) -> Country(c).
officiallyUses(c, l) -> Country(c), Language(l).
isMultilingual(c) <- officiallyUses(c, l1), officiallyUses(c, l2), l1 != l2.'
exec'
+isLarge("AU"), +isLarge("CA"), +isLarge("FR"), +isLarge("US").
+officiallyUses("AU", "English"), +officiallyUses("CA", "English").
+officiallyUses("CA", "French"), +officiallyUses("FR", "French").
+officiallyUses("LU", "French"), +officiallyUses("LU", "German").
+officiallyUses("LU", "Luxembourgish").
+officiallyUses("US", "English"), +officiallyUses("VA", "Italian"). '
错误信息:
谁能帮我理解什么是错的?