John Rolfe Isbell (October 27, 1930 – August 6, 2005)[1] was an American mathematician.
[2][3][4] He attended several undergraduate institutions, including the University of Chicago, where professor Saunders Mac Lane was a source of inspiration.
[3][4][6] After graduation, Isbell was drafted into the U.S. Army, and stationed at the Aberdeen Proving Ground.
Isbell published the first paper by John Rainwater, a fictitious mathematician who had been invented by graduate students at the University of Washington in 1952.
[4][8] Many of his works involved topology and category theory: In abstract algebra, Isbell found a rigorous formulation for the Pierce–Birkhoff conjecture on piecewise-polynomial functions.