If you are worried about 1.0 being a double constant and forcing the addition to be in double precision, then do: a = a + 1.0F; as specified in the ANSI C draft. -------- Rick Genter BBN Laboratories Inc. (617) 497-3848 10 Moulton St. 6/506 rgenter at bbn-labs-b.ARPA Cambridge, MA 02238 ...!{decvax,linus}!bbncca!rgenter