Disclosed here is the true account of the slaying in Mississippi of a Negro youth named Emmett Till. Last September in Sumner, Miss., a petit jury found the youth's admitted abductors not guilty of murder. In November, in Greenwood, a grand jury declined to indict them for kidnapping. Of the murder trial, the Memphis Commercial Appeal said: "Evidence necessary for convicting on a murder charge was lacking." But with truth absent, hypocrisy and myth have flourished. Now, hypocrisy can be exposed; myth dispelled. Here are the facts. Carolyn Holloway Bryant is 21, five feet tall, weighs 103 pounds. An Irish girl, with black hair and black eyes, she is a small farmer's daughter who, at 17, quit high school at Indianola, Miss., to marry a soldier, Roy Bryant, then 20, now 24. The couple have two boys, three and two; and they operate a store at a dusty crossroads called Money: post office, filling station and three stores clustered around a school and a gin, and set in the vast, lonely cotton patch that is the Mississippi Delta.