Guillermo Ricardo Simari is an Argentinian computer scientist. He is an international leader in defeasible reasoning

Defeasible reasoning

Defeasible reasoning is a kind of reasoning that is based on reasons that are defeasible, as opposed to the indefeasible reasons of deductive logic...

 and argument (logic) (see also argumentation theory

Argumentation theory

Argumentation theory, or argumentation, is the interdisciplinary study of how humans should, can, and do reach conclusions through logical reasoning, that is, claims based, soundly or not, on premises. It includes the arts and sciences of civil debate, dialogue, conversation, and persuasion...

), a national leader in logic programming

Logic programming

Logic programming is, in its broadest sense, the use of mathematical logic for computer programming. In this view of logic programming, which can be traced at least as far back as John McCarthy's [1958] advice-taker proposal, logic is used as a purely declarative representation language, and a...

 in Argentina, and one of the leaders of artificial intelligence

Artificial intelligence

Artificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...

 in South America. He has headed the Artificial Intelligence Research and Development Lab
at Universidad Nacional del Sur (Argentina) for twenty years, where he has personally mentored many internationally known students, such as Carlos Chesnevar, Alejandro Garcia, Marcelo Falappa, and Ana Maguitman, who have present impact in both the Spanish speaking and English speaking AI communities.

He completed his doctoral degree at Washington University in St. Louis

Washington University in St. Louis

Washington University in St. Louis is a private research university located in suburban St. Louis, Missouri. Founded in 1853, and named for George Washington, the university has students and faculty from all fifty U.S. states and more than 110 nations...

.