[rsecora]

Mathcad has the notebook metaphor (calculations embedded in live formatted documents) by 1986. Mathcad predates Mathematica by 1 year. [1]

[1] Mathcad 2.0 Ad from 1987, the oldest I have found in 10 min. https://books.google.es/books?id=sc4TnHAYBSUC&pg=PA42

[noneoftheabove]

Thanks for looking into it. Yes this is correct. Knowing what I hear about wolfram, even if there is a record in history wolfram claims He is the first.