Question: Steely Dan is an American rock band founded by core members Walter Becker (guitars, bass, backing vocals) and Donald Fagen (keyboards, lead vocals) in 1972. Blending elements of jazz, traditional pop, R&B, and sophisticated studio production with cryptic and ironic lyrics, the band enjoyed critical and commercial success starting from the early 1970s until breaking up in 1981. Throughout their career, the duo recorded with a revolving cast of session musicians, and in 1974 retired from live performances to become a studio-only band. Rolling Stone has called them "the perfect musical antiheroes for the Seventies".

Pretzel Logic was released in early 1974. A diverse set, it includes the group's most successful single "Rikki Don't Lose That Number" (No. 4) and a note-for-note rendition of Duke Ellington and James "Bubber" Miley's "East St. Louis Toodle-Oo". During the previous album's tour, the band had added vocalist-percussionist Royce Jones, vocalist-keyboardist Michael McDonald, and session drummer Jeff Porcaro (of Sonny & Cher). Porcaro contributed significantly to Pretzel Logic (as he would on future Steely Dan recordings), reflecting Steely Dan's increasing reliance on session musicians (including Dean Parks and Rick Derringer). Drummer Jeff Porcaro and Katy Lied pianist David Paich would go on to form Toto. Striving for perfection, Becker and Fagen sometimes asked musicians to record as many as forty takes of each track. Pretzel Logic was the first Steely Dan album to feature Walter Becker on guitar. "Once I met (session musician) Chuck Rainey", he explained, "I felt there really was no need for me to be bringing my bass guitar to the studio anymore". A rift began growing between Becker-Fagen and Steely Dan's other members (particularly Baxter and Hodder), who wanted to tour. Becker and Fagen disliked constant touring and wanted to concentrate solely on writing and recording. The other members gradually left the band, discouraged by this and by their diminishing roles in the studio. However, Dias remained with the group until 1980's Gaucho and Michael McDonald contributed vocals until the group's twenty-year hiatus after Gaucho. Baxter and McDonald went on to join The Doobie Brothers. Steely Dan's last tour performance was on July 5, 1974, a concert at the Santa Monica Civic Auditorium in California. A recording of the show's opening track, "Bodhisattva", was released as a B-side, and later appeared on the compilation album Gold. Becker and Fagen recruited a diverse group of session players for Katy Lied (1975), including Porcaro, Paich, and McDonald, as well as guitarist Elliott Randall, jazz saxophonist Phil Woods, saxophonist/bass-guitarist Wilton Felder, percussionist/vibraphonist/keyboardist Victor Feldman, keyboardist (and later producer) Michael Omartian, and guitarist Larry Carlton -- Dias, Becker, and Fagen being Steely Dan's only original members. The album went gold on the strength of "Black Friday" and "Bad Sneakers", but Becker and Fagen were so dissatisfied with the album's sound (compromised by a faulty DBX noise reduction system) that they publicly apologized for it (on the album's back cover) and for years refused to listen to it in its final form. Katy Lied also included "Doctor Wu" and "Chain Lightning".

Using a quote from the above article, answer the following question: what was pretzel logic
HHHHHH
Answer: Pretzel Logic was released in early 1974. A diverse set,

Question: Robert James Fischer (March 9, 1943 - January 17, 2008) was an American chess grandmaster and the eleventh World Chess Champion. Many consider him to be the greatest chess player of all time. Bobby Fischer showed great skill in chess from an early age; at 13, he won a brilliancy known as "The Game of the Century". At age 14, he became the US Chess Champion, and at 15, he became both the youngest grandmaster up to that time and the youngest candidate for the World Championship.

Bobby Fischer was born at Michael Reese Hospital in Chicago, Illinois, on March 9, 1943. His birth certificate listed his father as Hans-Gerhardt Fischer, also known as Gerardo Liebscher, a German biophysicist. His mother, Regina Wender Fischer, was a US citizen, born in Switzerland; her parents were Polish Jews. Raised in St. Louis, Missouri, Regina became a teacher, registered nurse, and later a physician. After graduating from college in her teens, Regina traveled to Germany to visit her brother. It was there she met geneticist and future Nobel Prize winner Hermann Joseph Muller, who persuaded her to move to Moscow to study medicine. She enrolled at I.M. Sechenov First Moscow State Medical University, where she met Hans-Gerhardt, whom she married in November 1933. In 1938, Hans-Gerhardt and Regina had a daughter, Joan Fischer. The reemergence of anti-Semitism under Stalin prompted Regina to go with Joan to Paris, where Regina became an English teacher. The threat of a German invasion led her and Joan to go to the United States in 1939. Hans-Gerhardt attempted to follow the pair but, at that time, his German citizenship barred him from entering the United States. Regina and Hans-Gerhardt had separated in Moscow, although they did not officially divorce until 1945. At the time of her son's birth, Regina was "homeless" and shuttled to different jobs and schools around the country to support her family. She engaged in political activism, and raised both Bobby and Joan as a single parent. In 1949, the family moved to Brooklyn, New York City, where she studied for her master's degree in nursing and subsequently began working in that field.

Using a quote from the above article, answer the following question: Did he have any siblings?
HHHHHH
Answer:
Joan Fischer.