Are Marc Rosset and Guillermo Vilas both tennis players?
yes
Marc Rosset
Marc Rosset (born 7 November 1970) is a former professional tennis player from Switzerland who is best remembered for winning the men's singles gold medal at the 1992 Olympic Games.
 He also won one Grand Slam doubles title at the French Open in 1992 partnering compatriot Jakob Hlasek.
Guillermo Vilas
Guillermo Vilas (] ; born 17 August 1952) is a retired professional tennis player from Argentina, N°1 of the Grand Prix tennis circuit's Season in 1974, 1975 and 1977, who won four majors, seven Grand Prix Super Series titles and 62 ATP titles.
 He was inducted into the International Tennis Hall of Fame in 1991.
 Known for his prolific match play, especially on clay, he became the second man to win more than 900 matches in the Open Era, and his number of match wins on clay are by far the most of the Era.
 His peak was the 1977 season during which he won two major titles (both on clay), had two long match win streaks of 46 all-surface and 53 on clay, and finished with an Open Era record of match wins.
 In 2005, Tennis magazine ranked him as the 15th-best male player of the preceding 40 years.
 He also popularized the between-the-legs tweener shot, also known as the "Gran Willy" in his honor.
Bettina Fulco
Bettina Fulco (born 23 October 1968) is a retired Argentine professional women's tennis player.
 She reached her highest ranking of No. 23 on October 10, 1988.
 Fulco began playing tennis at age 10 at the University Club in her hometown of Mar Del Plata, having been inspired to start because of the increased interest in the sport in Argentina due to Guillermo Vilas' success.
 As a junior, Bettina was among the best in the world, reaching the finals of the Orange Bowl 18-and-under championships in 1986, and finishing second in the rankings in 1986.
 She turned professional in 1987.
 Like many South American players, Bettina Fulco was considered a clay court specialist, and reached the quarterfinals of the French Open in 1988.
 Bettina beat Martina Navratilova in Houston 1994 for her biggest career victory.
 She also achieved victories over Conchita Martínez, Arantxa Sánchez Vicario, Hana Mandlíková, Katerina Maleeva, Manuela Maleeva, Magdalena Maleeva, Claudia Kohde-Kilsch, Lori McNeil and Nathalie Tauziat.
 She retired from professional tennis in 1998. 1977 Louisville Open
The 1977 Louisville Open, also known as the Louisville International Tennis Classic, was a men's tennis tournament played on outdoor clay courts at the Louisville Tennis Center in Louisville, Kentucky, USA.
 It was the eighth edition of the tournament and was held from 25 July through August 1, 1977.
 The tournament was part of the Grand Prix tennis circuit and categorized as a Four Star event.
 The singles final was won by first-seeded Guillermo Vilas who received $20,000 first prize money.
 It was Vilas' third title win at the tournament after 1974 and 1975. Guillermo Cañas
Guillermo Ignacio Cañas (born November 25, 1977), often referred to as Willy Cañas, is a retired Argentine professional tennis player.
 He was born in Argentina's capital, Buenos Aires, and named after Argentine tennis star Guillermo Vilas.
 His career-high singles ranking was World No. 8, achieved in June 2005.
 Cañas was the coach of Ernests Gulbis from July 2011 until May 2012 and became the coach of Teymuraz Gabashvili in 2015.
 Since January 2017, he is coaching former #1, Jelena Jankovic. 1993 Grand Prix de Tennis de Lyon – Doubles
Jakob Hlasek and Marc Rosset were the defending champions, but Rosset did not participate this year.
 Hlasek partnered Michiel Schapers, losing in the first round. 1977 Grand Prix (tennis)
The 1977 Colgate-Palmolive Grand Prix was a professional tennis circuit administered by the International Lawn Tennis Federation (ILTF, later the ITF) which served as a forerunner to the current Association of Tennis Professionals (ATP) World Tour and the Women's Tennis Association (WTA) Tour.
 The circuit consisted of the four modern Grand Slam tournaments and open tournaments recognised by the ILTF.
 The Colgate-Palmolive Masters is included in this calendar but did not count towards the Grand Prix ranking.
 Colgate-Palmolive was the new tour sponsor, taking over from Commercial Union.
 Guillermo Vilas won the Grand Prix circuit, having accumulated the most points (2,047), and received the largest share from the bonus pool ($300,000).
 The top eight points ranked singles players as well as the top four doubles teams qualified for the season-ending Masters tournament 1976 World Championship Tennis circuit
The 1976 World Championship Tennis circuit was one of the two rival professional male tennis circuits of 1976.
 It was organized by World Championship Tennis (WCT) and consisted of a schedule of 25 tournaments leading up to a singles WCT Finals play-off in Dallas and a doubles play-off in Kansas City in May.
 A total of 54 players participated, 30 players less than in the previous three years, and the group system used in the previous editions was replaced by a single pool.
 The U.S. Pro Indoor was the only tournament in which all players participated, all other tournaments had a 16 men draw.
 The season final was played by the eight best performers and was won by the Swede Björn Borg who defeated Guillermo Vilas from Argentina in four sets.
 The total prize money for the 1976 WCT circuit was $2,400,000, including a $320,000 Avis Challenge Cup round–robin special event played in Hawaii in January and May. Guillermo Coria
Guillermo Sebastián Coria (born 13 January 1982), nicknamed El Mago ("The Magician" in Spanish), is a retired professional tennis player from Argentina.
 He reached a career-high Association of Tennis Professionals (ATP) world No. 3 singles ranking on May 3, 2004.
 He was named after French Open champion and compatriot Guillermo Vilas. 1978 U.S. Pro Tennis Championships
The 1978 U.S. Pro Tennis Championships was a men's tennis tournament played on outdoor green clay courts (Har-Tru) at the Longwood Cricket Club in Boston, USA.
 The event was part of the 1978 Grand Prix circuit.
 It was the 51st edition of the tournament and was held from August 21 through August 28, 1978.
 Despite pressure to switch to a hard court surface from the Association of Tennis Professionals (ATP) and some leading players, in line with the surface change made that year by the US Open which directly followed the Boston event, the tournament organization elected to remain a clay court tournament in 1978.
 Several top players including Björn Borg, Guillermo Vilas and Jimmy Connors elected not to play the tournament.
 Fourth-seeded and defending champion Manuel Orantes won the singles title and the accompanying $32,000 first-prize money.
 The final was delayed until Tuesday, August 29 due to rain.