Communications of the ACM,
Vol. 64 No. 7, Pages 13-15
10.1145/3464933
The modern world runs on software. From smartphones and automobiles to medical devices and power plants, executable code drives insight and automation. However, there is a catch: computer code often contains programming errors—some small, some large. These glitches can lead to unexpected results—and systematic failures.
"In many cases, software flaws don't make any difference. In other cases, they can cause massive problems," says Kathleen Fisher, professor and chair of the computer science department at Tufts University and a former official of the U.S. Defense Advanced Research Projects Agency (DARPA).
3 Comments
J Paul Gibson
The specification "For all values j and k such that 0 <= j < k < N, it must be the case that B[i] < B[j]." defines indexes j and k, yet uses indexes i and j. It also is problematic if the initial array contains elements of equal value. These are not just incompleteness issues.
Lawrence Markosian
The inventor of TLA+ is Leslie Lamport, 2013 ACM Turing Award winner:
"For fundamental contributions to the theory and practice of distributed and concurrent systems, notably the invention of concepts such as causality and logical clocks, safety and liveness, replicated state machines, and sequential consistency." Lamport's web site, lamport.org, discusses TLA+ and some of its industrial applications.
Samuel Greengard
Thanks, J. Paul and Lawrence for your comments. I appreciate you pointing out these things, especially Leslie Lamport's contributions.
Displaying all 3 comments
Log in to Read the Full Article
Purchase the Article
Log in
Create a Web Account
If you are an ACM member, Communications subscriber, Digital Library subscriber, or use your institution's subscription, please set up a web account to access premium content and site
features. If you are a SIG member or member of the general public, you may set up a web account to comment on free articles and sign up for email alerts.
![[article image]](https://cacm.acm.org/system/assets/0004/0219/061821_ClassCentral_Formal-Software.large.jpg?1623866962&1623866962 "chip with a check mark, illustration")
J Paul Gibson
The specification "For all values j and k such that 0 <= j < k < N, it must be the case that B[i] < B[j]." defines indexes j and k, yet uses indexes i and j. It also is problematic if the initial array contains elements of equal value. These are not just incompleteness issues.