# Rohit Jivanlal Parikh

**Rohit Jivanlal Parikh** (born November 20, 1936) is a mathematician, logician, and philosopher who has worked in many areas in traditional logic, including recursion theory and proof theory. He is a Distinguished Professor at the City University of New York (CUNY).

Rohit Jivanlal Parikh | |
---|---|

Born | |

Residence | United States |

Nationality | India, United States |

Alma mater | Harvard University, PhD Mathematics, 1962; Harvard College, AB with highest honors in Physics, 1957 |

Known for | Work on recursion theory, proof theory, non-standard analysis, ultrafinitism, dynamic logic, logic of knowledge, philosophical logic, social software, Parikh's theorem |

Awards | William Lowell Putnam Mathematical Competition Prize Winner, 1955, 1956, 1957; William Lowell Putnam Fellow 1957; Phi Beta Kappa, Harvard 1957. Gibbs Prize, Bombay University, 1954 |

Scientific career | |

Fields | Mathematics, logic, philosophy, computer sciences, economics |

Institutions | City University of New York |

Doctoral advisor | Hartley Rogers, Jr Burton Dreben |

## Research

Parikh's catholic attitude towards logic has led to work on topics like vagueness, ultrafinitism, belief revision, logic of knowledge, game theory and social software (social procedure). This last area seeks to combine techniques from logic, computer science (especially logic of programs) and game theory to understand the structure of social algorithms. Examples of such are elections, transport systems, lectures, conferences, and monetary systems, all of which have properties of interest to those who are logically inclined.

Parikh's theorem, stating that regular languages and context-free languages have the same sets of letter frequency vectors, is named after him. Among his other contributions is the introduction of bounded arithmetic and the logic of games.

## Personal life and politics

Rohit Parikh was married from 1968 to 1994 to Carol Parikh (née Geris), who is best known for her prize-winning stories and for her influential biography of Oscar Zariski, *The Unreal Life of Oscar Zariski*. They have two children, Vikram (born 1969) and Uma (born 1974).

In 2018, a Facebook post by Parikh, calling for deportation of all illegal immigrants[1] and claiming that Hispanic immigrants are insufficiently educated compared to Indian immigrants like him, led Brooklyn College students to public protests and calls for the university to discipline him.[2] The president of Brooklyn College Michelle Anderson called his remarks "antithetical to the fundamental values of Brooklyn College."[3] Defending his position in an interview to a CW-affiliate WPIX, Parikh claimed he had not meant that Hispanics in general were dumber than Indians in general, but rather that his comparison of intellectual abilities of Hispanics and Indians had applied only to those who had immigrated to the United States. "There are a lot of stupid people in India but they don't come here," he explained.[2]

## Posts

- Editor, International Journal of the Foundations of Computer Science, 1990–1995
- Editor, Journal of Philosophical Logic, 2000–2003

## Awards and recognition

- William Lowell Putnam Mathematical Competition Prize Winner, 1955, 1956, 1957
- Gibbs Prize, Bombay University, 1954

## Students

- Alessandra Carbone[4]

## Academic and research appointments

- Distinguished Professor, City University of New York, (Brooklyn College and CUNY Graduate Center), 1982–present
- Professor, Mathematics, Boston University, 1972–1982
- Visiting Professor, Mathematics, Courant Institute, 1981
- Associate Professor, Mathematics, Boston University, 1967–1972
- Visiting Associate Professor, Mathematics, SUNY at Buffalo, 1971–1972
- Lecturer, Bristol University, 1965–1967
- Reader, Panjab University, 1964–1965
- Instructor, Stanford University 1961–1963
- Visiting Appointments at Stanford, TIFR Bombay, ETH Zurich, and Caltech

## Main publications

- Existence and Feasibility in Arithmetic, Jour. Symbolic Logic 36 (1971) 494–508.
- On the Length of Proofs, Transactions of the Amer. Math. Soc. 177 (1973) 29–36.
- (With M. Parnes) Conditional Probability can be Defined for Arbitrary Pairs of Sets of Reals, Advances in Math 9 (1972) 520–522.
- (With D.H.J. de Jongh) Well Partial Orderings and Hierarchies, Proc. Kon. Ned. Akad. Sci Series A 80 (1977) 195–207.
- (With D. Kozen) An Elementary Completeness Proof for PDL Theoretical Computer Science 14 (1981) 113–118.
- The Problem of Vague Predicates, in Logic, Language and Method Ed. Cohen and Wartofsky, Reidel (1982) 241–261.
- The Logic of Games and its Applications, Annals of Discrete Math., 24 (1985) 111–140.
- (With R. Ramanujam) Distributed Processing and the Logic of Knowledge, in Logics of Programs, Springer Lecture Notes in Computer Science, 193 pp. 256–268.
- Communication, Consensus and Knowledge, (with P. Krasucki), Jour. Economic Theory 52 (1990) pp. 178–189.
- Knowledge and the Problem of Logical Omniscience ISMIS- 87 (International Symp. on Methodology for Intelligent Systems), North Holland (1987) pp. 432–439.
- Finite and Infinite Dialogues, in the Proceedings of a Workshop on Logic from Computer Science, Ed. Moschovakis, MSRI publications, Springer 1991 pp. 481–498.
- Vagueness and Utility: the Semantics of Common Nouns in Linguistics and Philosophy 17 1994, 521–35.
- Topological Reasoning and The Logic of Knowledge (with Dabrowski and Moss) Annals of Pure and Applied Logic 78 (1996) 73–110.
- Belief revision and language splitting, in Proc. Logic, Language and Computation, Ed. Moss, Ginzburg and de Rijke, CSLI 1999, pp. 266–278 (earlier version appeared in 1996 in the preliminary proceedings).
- (with Samir Chopra), Relevance Sensitive Belief Structures, Annals of Mathematics and Artificial Intelligence, 28(1-4): 259–285 (2000).
- Social Software, Synthese, 132, Sep 2002, 187–211.
- (with Jouko Vaananen), Finite information logic, Annals of Pure and Applied Logic, 134 (2005) 83–93.
- (With R. Ramanujam), A Knowledge based Semantics of Messages, Jour. Logic, Language and Information, 12 2003, 453–467.
- Levels of Knowledge, Games, and Group Action, Research in Economics, 57 2003, 267–281.

## References

- Algar, Selim (October 23, 2018). "Professor faces backlash after questioning desirability of Hispanic immigrants". New York Post. Retrieved December 30, 2018.
- Chasmar, Jessica (October 24, 2018). "Brooklyn College prof. under fire for asking whether Hispanic immigrants are what 'America needs'". The Washington Times. Retrieved December 30, 2018.
- Kadirgamar, Skanda (December 6, 2018). "After 2 Brooklyn College Professors Spouted Hate, Students Want Restitution". The Nation. Retrieved December 30, 2018.
- "Rohit Parikh - The Mathematics Genealogy Project".
*www.genealogy.math.ndsu.nodak.edu*. Retrieved 2019-03-16.