{}({}({}()) {}()) - [a] r1, 1.1{} 1.2{} | r2, 2.1 2.2 [1.1] r1.1.1, 1.1.1.1{} 1.1.1.2{} [2.1] r2.2.1, 2.1.1.1{} 2.1.1.2{} cate-trans |/