1NF is defined as eliminating nested relations. I assumed "[ cryptography, databases]" in the example represent a nested relation. 1NF is not defined in terms

1NF is defined as eliminating nested relations. I assumed "[ cryptography, databases]" in the example represent a nested relation. 1NF is not defined in terms of what you want to do with the the data, it is defined in terms of domains, i.e data types. If a column allows nested tables, it violates 1NF. "Atomic" in the context of 1NF means atomic wrt. the relational algebra. Eg. if we have: Student: Bob, classes: [ cryptography, databases] Student: Alice, classes: [] Is it possible to select from this all students which has cryptography as a class, using the standard relational operators (project, filter, join)?