0:int - x was not enough for those balancing(?) and promoting thing? On Oct 17, 2014, at 12:07 PM, Charles Forsyth > wrote: it's building a tree for (0:int-(0:int-x)) which later transformations will simplify to x, but having done "the usual arithmetic conversions" balancing and promoting 0s and x as required, if it's char/int/long/vlong.