question: What is the date of death of Constance Of Burgundy's father?
context: [["Robert I, Duke of Burgundy", ["Robert I (1011 \u2013 21 March 1076), known as Robert the Old and , was Duke of Burgundy from 1032 to his death.", "Robert was son of King Robert II of France and Constance of Arles.", "His brother was Henry I of France."]], ["Isabella of Bourbon", ["Isabella of Bourbon, Countess of Charolais( 1434 \u2013 25 September 1465) was the second wife of Charles the Bold, Count of Charolais and future Duke of Burgundy.", "She was a daughter of Charles I, Duke of Bourbon and Agnes of Burgundy, and the mother of Mary of Burgundy, heiress of Burgundy."]], ["Constance of Burgundy", ["Constance of Burgundy (8 May 1046 \u2013 1093) was the daughter of Duke Robert I of Burgundy and Helie de Semur-en-Brionnais.", "She was Queen consort of Castile and Le\u00f3n by her marriage to Alfonso VI of Le\u00f3n and Castile.", "She was the granddaughter of King Robert II of France, the second monarch of the French Capetian dynasty.", "She was the mother of Urraca of Le\u00f3n, who succeeded her father in both Castile and Le\u00f3n."]], ["Theodred II (Bishop of Elmham)", ["Theodred II was a medieval Bishop of Elmham.", "The date of Theodred's consecration unknown, but the date of his death was sometime between 995 and 997."]], ["Sibylla of Burgundy, Duchess of Burgundy", ["Sybilla of Burgundy( 1065 \u2013 1103), was a French noble, Duchess consort of Burgundy by marriage to Eudes I, Duke of Burgundy.", "She was a daughter of William I, Count of Burgundy and Stephanie.", "She was married to Eudes I, Duke of Burgundy in 1080.", "Children:"]], ["Joan III, Countess of Burgundy", ["Joan III of Burgundy( 1/2 May 1308 \u2013 10/15 August 1347), also known as Joan of France was a reigning Countess of Burgundy and Artois in 1330 \u2013 1349, She was also Duchess of Burgundy by marriage to Odo IV, Duke of Burgundy.", "She was the eldest daughter of King Philip V of France and Countess Joan II of Burgundy."]], ["Agnes of France, Duchess of Burgundy", ["Agnes of France( c. 1260 \u2013 19 December 1327) was a Duchess of Burgundy by marriage to Robert II, Duke of Burgundy.", "She served as regent of Burgundy during the minority of her son in 1306 \u2013 1311."]], ["Florine of Burgundy", ["Florine of Burgundy( 1083\u20131097) was a French crusader.", "She was the daughter of Eudes I, Duke of Burgundy and Sybilla of Burgundy.", "Her maternal grandfather was William I, Count of Burgundy.", "Florine was married to Sweyn the Crusader, a son of Sweyn II of Denmark."]], ["Constance of Arles", ["Constance of Arles( c. 986 \u2013 28 July 1032), also known as Constance of Provence, was queen of France as the third spouse of King Robert II of France."]], ["Hugh IV, Duke of Burgundy", ["Hugh IV of Burgundy( 9 March 1213 \u2013 27 or 30 October 1272) was Duke of Burgundy between 1218 and 1272.", "Hugh was the son of Odo III, Duke of Burgundy and Alice de Vergy."]]]
supporting_facts: [["Constance of Burgundy", 0], ["Robert I, Duke of Burgundy", 0]]
evidences: [["Constance of Burgundy", "father", "Robert I"], ["Robert I", "date of death", "21 March 1076"]]
answer: 21 March 1076