Assemblyman Art Agnos (D-San Francisco) has admitted failing to pay federal and state taxes on $65,000 worth of income in 1983 and 1984 until a month ago, explaining that the tardiness in payment was an oversight. Agnos, a candidate for San Francisco mayor, told the San Francisco Chronicle that the previously unreported income came from a land deal involving Sacramento developer Angelo Tsakopoulos, whom Agnos called his best friend. Agnos' original investment was $4,500, which was borrowed from Tsakopoulos. Explaining that he had not noticed that he had failed to report the $65,000 until last month, Agnos said: "The important thing is we found it, and it is corrected now. I certainly don't want to cheat the government or anyone else."