Is compound(i,n) meaning compound interest: (1+i)**n part of Fortran? If so, what is compound(NaN,0)? --- Fred J. Tydeman Tydeman Consulting tydeman at tybor.com Testing, numerics, programming +1 (775) 287-5904 Vice-chair of PL22.11 (ANSI "C") Sample C99+FPCE tests: http://www.tybor.com Savers sleep well, investors eat well, spenders work forever.