January 22, 1985

Under this heading, The Times amplifies articles or rectifies what the editors consider significant lapses of fairness, balance or perspective.

Last year, when most of this city's major banks were mired in trauma and uncertainty, the American National Bank and Trust Company of Chicago, the city's fifth-largest bank, put together a record year by capitalizing on the problems of its hometown competitors. It did this by continuing to do what it does best: serving the highly profitable ''middle market'' of small and medium-sized companies. So successful was 1984 for American National that its earnings jumped by 32 percent, its client roster by more than 20 percent and its loans outstanding by 30 percent. In addition, the First Chicago Corporation, the city's largest bank holding company, impressed by American National's record, acquired the bank from the Walter E. Heller International Corporation last May.

A caption and article in Business Day yesterday about market specialists on the New York Stock Exchange misspelled the name of Michael Creem, and of his firm, Creem & Creem.

A cross two stories high adorns an outside wall of St. Brigid School on the Lower East Side, and inside the building there are crucifixes in all but three classrooms. Overt signs of religion are banned from those three rooms of the Roman Catholic school because teachers assigned by the Board of Education work in them. Arrangements like this, with church and state carrying out educational functions in close proximity, serve 20,000 students in 253 of the city's nonpublic schools. All but one of the schools are under religious auspices, mostly Catholic or Jewish, and altogether $30 million in Federal money is spent by the Board of Education on remedial education programs in the parochial schools.

COMPUTERS have long been able to draw fairly simple shapes such as balls, blocks and even airplane wings. But when it came to drawing more complex natural phenomena, like wispy clouds or jagged mountain peaks, computers could manage only crude approximations. Now, however, a once obscure mathematical concept known as fractals is allowing computer scientists to surmount those barriers. Fractals are mathematical curves that define some order in the midst of seemingly chaotic phenomena, like the shape of a coastline or cloud. And they are becoming important not only for computer graphics, but for many areas of science involving seemingly random phenomena, including the turbulent flow of fluids, the fracturing of metals, the clustering of galaxies in the universe, the distribution of vegetation in Georgia's Okefenokee Swamp,