>>>>> "L" == Luigi Ballabio <luigi.ballabio / riskmap.net> writes: Add >> class One >> def + (x) >> x+1 >> end def coerce(x) [x, 1] end >> end L> Sort of __radd__ in Python? it will work also with '3 * one' and 'one * 3' if you define 'def *(x)' (or with -) You have a more complete example in Complex.rb Guy Decoux