Then would someone mind clarifying this statement by Paul Graham? "... A famous example of this is Steele & Sussman's discovery, during the writing of Scheme,

Then would someone mind clarifying this statement by Paul Graham? "... A famous example of this is Steele & Sussman's discovery, during the writing of Scheme, that Actors and closures were the same thing." -ref: http://people.csail.mit.edu/gregs/ll1-discuss-archive-html/msg01552.html http://people.csail.mit.edu/gregs/ll1-discuss-archive-html/m...