Question: What French mathematician, whose father was a tax collector in Rouen, did Oleg Khoma do research on?

Context paragraphs:
Oleg Khoma: Oleg Khoma (born October 30, 1966) is Ukrainian historian of European philosophy, researcher, translator and commentator on 17th- and 20th-century French philosophy.  Researcher of Blaise Pascal, Rene Descartes and Nicolas Malebranche.

Pearl Long Cullen: Pearl Long Cullen (July 3, 1890 - November 6, 1979) was the first woman to hold a constitutional office in the state of Florida.  She was also the first woman to be elected to a constitutional office in the state of Florida.  In 1923, upon the death of her father, who was the elected tax collector, Cullen was appointed by the governor to serve out her father's term.  In 1925, Boyce Williams won the election as tax collector.  Cullen continued to work in the tax office, and, in 1941, was once again appointed by the governor as tax collector of Lake County, Florida.  In 1944, Cullen successfully sought the office and served consecutive terms as tax collector until her retirement in 1959.  No other woman prior to Cullen's appointment in 1923, or until her win in 1941, had held a constitutional office in Florida.

Scott Randolph: Scott Randolph (born October 17, 1973) is a Democratic politician who has served as the Orange County Tax Collector since 2013.  Prior to his election as Tax Collector, he served as a member of the Florida House of Representatives, representing the 36th District from 2006 to 2012.

Anne M. Gannon: Anne M. Gannon (born December 23, 1947) is a Democratic politician who currently serves as the Palm Beach County Tax Collector.  Prior to her election as Tax Collector, she served as a member of the Florida House of Representatives, representing the 88th District from 2000 to 2002, and the 86th District from 2002 to 2006.

John M. Drew: John M. Drew (born May 31, 1973) is the Tax Collector of Nassau County, Florida.  Drew was first appointed Tax Collector by Governor Jeb Bush in May 2006.  He was elected to the office later that year and ran unopposed in 2008 and 2012.

Maral (tax): Maral or Marala ("death duty") is an unpopular tax system which was practiced in Sri Lanka.  The tax was applied on property after the death of person, who had the rights on property.  Two-third of property could own by kinsmen or heirs upon owner’s death and one-third could levy by the state.  If there were no kinsmen, the entire property could levy by the state.  Similar practice was practiced in India too.  However, Christians were exception to the tax during Portuguese rule and Maral tax collector was appointed to collect the tax.

Blaise Pascal: Blaise Pascal ( ; ] ; 19 June 1623 – 19 August 1662) was a French mathematician, physicist, inventor, writer and Catholic theologian.  He was a child prodigy who was educated by his father, a tax collector in Rouen.  Pascal's earliest work was in the natural and applied sciences where he made important contributions to the study of fluids, and clarified the concepts of pressure and vacuum by generalising the work of Evangelista Torricelli.  Pascal also wrote in defence of the scientific method.

Ohio Township, Allegheny County, Pennsylvania: Ohio Township is a township of the Second Class in Allegheny County, Pennsylvania, United States.  Ohio Township elects a board of three (3) Supervisors, a property tax collector, and a constable, each for a term of six (6) years, with exception of the tax collector, whose term of office is four (4) years.  The day to day business of the township is managed by a Township Manager serving at will and is supported by an administrative staff.  In addition to the Administration Office, the Police Department, Road Department, and Recreation Department are also under the direct administration of the Board of Supervisors.  The population was 4,757 at the 2010 census.  The township is located 9 mi northwest of Pittsburgh.  There is no central business district, but there are a few small shops in the Mt. Nebo area.  A new shopping center has been built called Mt. Nebo Pointe.  In recent years, several retail outlets have been built near the Camp Horne Road interchange of Interstate 279.

Harelle: The Harelle (] ; from "haro") was a revolt that occurred in the French city of Rouen in 1382 and followed by the Maillotins Revolt a few days later in Paris, as well as numerous other revolts across France in the subsequent week.  France was in the midst of the Hundred Years War, and had seen decades of warfare, widespread destruction, high taxation, and economic decline, made worse by bouts of plague.  In Rouen, the second largest city in the kingdom, the effects of the war were particularly felt.  Tensions had been building nationally for nearly a year following the death of Charles V; on his deathbed he repealed many of the war taxes he had previously imposed.  With the re-imposition of the taxes months later, a localized revolt led by Rouen's guilds, occurred in the city and was followed by many similar such incidents across the kingdom.  Charles VI traveled with an army led by his uncle and regent, Philip the Bold Duke of Burgundy, from Paris.  Paris itself revolted shortly after the army left the city.  After returning to Paris to deal with the rebels there, the Duke and King traveled with an army to Rouen to end the revolt.  The leaders of the Harelle in Rouen feared execution on the scale that occurred in Paris, and resolved to not resist the army.  Twelve leaders of the revolt were executed, the city's rights were revoked and it was put under the rule of a royal governor, and a fine of 100,000 francs was imposed.  Despite the victory, the King was unable to re-enforce the taxation that prompted the revolt, and spent most of the next two years putting down similar tax revolts around the kingdom that followed the example of Rouen.  The Harelle was one of many popular revolts in late medieval Europe, including the English peasants' revolt of 1381 one year earlier, all part of a larger crisis of the Late Middle Ages.

Pharisee and the Publican: The parable of the Pharisee and the Publican (or the "Pharisee and the Tax Collector") is a parable of Jesus that appears in the Gospel of Luke.  In Luke 18:9-14, a Pharisee, obsessed by his own virtue, is contrasted with a tax collector who humbly asks God for mercy.

Supporting paragraphs: Oleg Khoma Blaise Pascal
Answer: Researcher of Blaise Pascal