A money quote, from your first link: Here's what I did. For a set of problems, of increasing difficulty, I would write a solution procedure, using the notation

A money quote, from your first link: Here's what I did. For a set of problems, of increasing difficulty, I would write a solution procedure, using the notation of A Programming Language I would then ask the graduate student assigned to me to: program the procedure in any programming language he chose, execute the procedure for a representative set of data values give me his program and answers so that I could compare them with the specifications I had written and the answers I had previously calculated. The result, which I still find surprising and impressive, was: In every case, what was programmed was exactly what I specified.