Bell and Riordan
In the 1930s and 1940s, Eric Temple Bell tried unsuccessfully to make this kind of argument logically rigorous. The combinatorialist John Riordan in his book Combinatorial Identities published in the 1960s, used techniques of this sort extensively.
Read more about this topic: Umbral Calculus
Famous quotes containing the word bell:
“His are the quiet steeps of dreamland,
The waters of no-more-pain;
His ram’s bell rings ‘neath an arch of stars,
“Rest, rest, and rest again.””
—Walter De La Mare (1873–1956)