Let M = { ∀a, t.(AuthorOf(a, t)→ ∃g.BookInfo(t, a, g)) }, I1 = { AuthorOf(nabokov, lolita), AuthorOf(tolkien, lotr) }. Then I2 = { BookInfo(lolita, nabokov, n1), BookInfo(lotr, tolkien, n2) } is a universal solution. Data Exchange Example Let M = { ∃AuthorOf− v ∃BookGenre, AuthorOf− v WrittenBy, TaxNumber v SSN }, T1 = { ∃AuthorOf v Author, Author v ∃TaxNumber }, A1 = { AuthorOf(nabokov, lolita...