Question: Were Mariaan de Swardt and Ken Rosewall both professional tennis players?

<P0-S0> Mariaan de Swardt (born 18 March 1971) is a former tennis player from South Africa, who played as a professional from 1988 to 2001. <P0-S1>  She twice represented her native country at the Summer Olympics, in 1992 and 1996, and was a member of the South African Fed Cup Team in 1992 and 1994–1997. <P0-S2>  In 2006, de Swardt became a U.S. citizen. <SEP> <P1-S0>  In his 1979 autobiography Kramer included both Gonzales and Rosewall in his list of the 21 greatest players of all time. <P1-S1>  1 player in the world. <P1-S2>  (In fact, Gonzales only beat him 50–26, and it was always competitive.)" <P1-S3>  Before their opening match in Melbourne, Kramer went to Gonzales and asked him to "carry" Rosewall, giving him a better share of the gate to gain his assent. <P1-S4>  Rosewall became the world's best player upon Gonzales's semi-retirement in 1961 and held that position either by himself or sharing it with others for six years. <P1-S5> American tennis player Pancho Gonzales had a long-running rivalry with Australian Ken Rosewall. <P1-S6>  Six years older than Rosewall, 13 years later, in 1970, Gonzales defeated him in 6–4, 6–4, in the 199th and next-to-last match they ever played—Gonzales was 42 years old at the time and Rosewall was considered to be the co-No. <P1-S7>  Gonzales did try to carry out his part of the deal for a few matches, but then called it off, telling Kramer that he was no longer able to play his normal game. <P1-S8>  Gonzales is still sometimes considered to be a candidate for the greatest tennis player of all time; he was the dominant player of the 1950s and still holds the men's all-time record of being ranked world No. 1 for eight years. <P1-S9>  "It was... obvious that Rosewall was not the pushover I had feared. <P1-S10>  He then engaged in a round-the-world, head-to-head tour against Gonzales, the defending world's champion, over the next five months, winning 26 matches but losing 50. <P1-S11>  I was afraid that Gorgo would eat him alive and put us out of business the rest of the way. <P1-S12>  That great volley of his hadn't been developed yet. <P1-S13>  Rosewall was signed in 1956 by the promoter Jack Kramer, a former #1 player himself, to join his small band of touring professionals in 1957. <P1-S14>  Kramer agreed. <SEP> <P2-S0> Kenneth Robert Rosewall {'1': ", '2': ", '3': 'AM, MBE', '4': "} (born 2 November 1934) is a former world top-ranking amateur and professional tennis player from Australia. <P2-S1>  He won a record 23 tennis Majors including 8 Grand Slam singles titles and before the Open Era a record 15 Pro Slam titles and a record 35 Major finals overall. <P2-S2>  He won the Pro Grand Slam in 1963. <P2-S3>  Rosewall won 9 slams in doubles with a career double grand slam. <P2-S4>  He is considered to be one of the greatest tennis players of all time. <P2-S5>  He had a renowned backhand and enjoyed a long career at the highest levels from the early 1950s to the early 1970s. <P2-S6>  Rosewall was one of the two best male players for about nine years and was the World No. 1 player for a number of years in the early 1960s. <P2-S7>  He was ranked among the top 20 players, amateur or professional, every year from 1952 through 1977. <P2-S8>  Rosewall is the only player to have simultaneously held Pro Grand Slam titles on three different surfaces (1962–1963). <P2-S9>  At the 1971 Australian Open he became the first male player during the open era to win a Grand Slam tournament without dropping a set. <SEP> <P3-S0> The 1999 Wimbledon Championships – Women's Doubles was the women's doubles event of the hundred-and-thirteenth edition of Wimbledon, the third Grand Slam of the year, the most prestigious tournament on grass courts, and the oldest tennis tournament in the world. <P3-S1>  Martina Hingis and Jana Novotná were the defending champions but only Novotná competed that year with Natasha Zvereva. <P3-S2>  Novotná and Zvereva lost in the semifinals to Mariaan de Swardt and Elena Tatarkova.