# The Essential Barbara Liskov

DevFeed: [The Essential Barbara Liskov](<https://devfeed.tech/articles/the-essential-barbara-liskov-12463.md>)

Original publisher: [Read original article](<http://brooker.co.za/blog/2014/09/21/liskov-pub.html>)

Author: Marc Brooker

Published: 2014-09-21T00:00:00Z

Content type: opinion

Language: en

Sources: [Marc Brooker's Blog](<https://devfeed.tech/sources/marc-brooker-s-blog.md>), [Marc Brooker's Blog](<https://devfeed.tech/sources/marc-brooker-s-blog-2.md>)

Topics: [Computer science](<https://devfeed.tech/topics/computer-science.md>), [distributed-systems](<https://devfeed.tech/topics/distributed-systems.md>), [Replication](<https://devfeed.tech/topics/replication.md>), [Availability](<https://devfeed.tech/topics/availability.md>), [Protocol (disambiguation)](<https://devfeed.tech/topics/protocol.md>)

Tags: [availability](<https://devfeed.tech/tags/availability.md>), [distributed-systems](<https://devfeed.tech/tags/distributed-systems.md>), [publications](<https://devfeed.tech/tags/publications.md>), [replication](<https://devfeed.tech/tags/replication.md>), [research](<https://devfeed.tech/tags/research.md>), [science](<https://devfeed.tech/tags/science.md>), [systems](<https://devfeed.tech/tags/systems.md>), [types](<https://devfeed.tech/tags/types.md>), [worth-reading](<https://devfeed.tech/tags/worth-reading.md>)

## AI overview

An overview of selected Barbara Liskov papers, covering behavioral subtyping and the Liskov Substitution Principle, as well as replication and highly available distributed systems through Viewstamped Replication. The article emphasizes the papers' historical significance, readability, and relevance to working programmers.

## Source excerpt

The Essential Barbara Liskov Some of my favorite Barbara Liskov publications. Barbara Liskov is one of the greats of computer science. Over a research career nearing 45 years, she's had a resounding impact on multiple different fields, and received an impressive list of honors and awards, including the 2009 Turing Award. In the same spirit as The Essential Leslie Lamport and The Essential Nancy Lynch, I thought I'd write about some of my favorite Liskov papers. These are just papers I like or found particularly interesting, and I'm likely to have missed some you like. What does it mean for one type to be a subtype of another? We argue that this is a semantic question having to do with the behavior of the objects of the two types: the objects of the subtype ought to behave the same as those of the supertype as for as anyone or any program using the supertype objects can tell. Data abstraction and hierarchy, A behavioral notion of subtyping and Behavioral subtyping using invariants and constraints, are why most working programmers would recognize Liskov's name. The Liskov Substitution Principle, widely known as the L in SOLID, is a widely-followed rule about the relationship between the behavior of its supertypes and subtypes. I'll readily admit that types are an area of computer science that I'm not very familiar with, but I found these papers easy to follow and very applicable. For the working programmers, there's not much material there that isn't covered in the wiki page, but it's worth reading to see how Liskov lays out the arguments for the principle. If you're interested in the history and thinking behind rules, these are great papers to read. Availability is achieved through replication. Transaction processing depends on forcing information to backups so that a majority of cohorts know about particular events. Viewstamped Replication: A New Primary Copy Method to Support Highly Available Distributed Systems deserves to be recognized as one of the most influent