Seven sorts of programs
R. S. Scowen, Zbigniew Ciechanowicz · ACM SIGPLAN Notices · 1982
When computer scientists talk of debugging programs they mean detecting and removing the errors. This naturally encourages an over-simple view that a program is either right or wrong. This note suggests that there are at least seven degrees of correctness for a program. A simple Algol 60 program that calculates the average of up to ten numbers is used as an example.This note originally appeared as an appendix to a report on Compiler Validation published by NPL [SCOW80].