Thanks for a polite disagreement, but I believe you are wrong (not saying you are!). IIRC Codd defined relation valued attributes and also associated operators Group and Ungroup.
https://www.oreilly.com/library/view/sql-and-relational/9781...also https://shark.armchair.mb.ca/~erwin/RA_Intro.htm
"
Relations are, themselves, values too, and relation attributes can therefore be declared to be of another relation type. Such attributes are called 'Relation-valued attributes' (RVA's for short).
In the RA, two operators are available that allow us to manipulate relations in connection with RVA's : GROUP and UNGROUP
"
Like I said, I'm a bit out of my depth here so take the above as evidence rather than proof that such things existed, but I'm pretty sure I saw this, hand-drawn, in one of Codd's original papers.
.
Edit: you are right
"Codd proposed a normal form thathe called first normal form (1NF), and he included a requirement for 1NF in his definitions for 2NF,3NF, and subsequently BCNF. Under 1NF as he defined it, relation-valued attributes were “outlawed”;that is to say, a relvar having such an attribute was not in 1NF."
https://fliphtml5.com/qprz/cxon/basic/201-235
also https://shark.armchair.mb.ca/~erwin/RA_Intro.htm
"
Relations are, themselves, values too, and relation attributes can therefore be declared to be of another relation type. Such attributes are called 'Relation-valued attributes' (RVA's for short).
In the RA, two operators are available that allow us to manipulate relations in connection with RVA's : GROUP and UNGROUP
"
Like I said, I'm a bit out of my depth here so take the above as evidence rather than proof that such things existed, but I'm pretty sure I saw this, hand-drawn, in one of Codd's original papers.
.
Edit: you are right
"Codd proposed a normal form thathe called first normal form (1NF), and he included a requirement for 1NF in his definitions for 2NF,3NF, and subsequently BCNF. Under 1NF as he defined it, relation-valued attributes were “outlawed”;that is to say, a relvar having such an attribute was not in 1NF."
https://fliphtml5.com/qprz/cxon/basic/201-235