Zoom. https://umd.zoom.us/j/93825468763?pwd=UXlYZmVkVndXb1owMkpYb2tOQjZFQT09

Title. I am not a Number — I am a Free Variable

PDF. https://www.cs.ru.nl/~james/RESEARCH/haskell2004.pdf

Abstract. In this paper, we show how to manipulate syntax with binding using a mixed representation of names for free variables (with respect to the task in hand) and de Bruijn indices [5] for bound variables. By doing so, we retain the advantages of both representations: naming supports easy, arithmetic-free manipulation of terms; de Bruijn indices eliminate the need for α-conversion. Further, we have ensured that not only the user but also the implementation need never deal with de Bruijn indices, except within key basic operations.