Hidden text[Rosie] It's a subtlety that I think even French poets would get away with. Similar to 'glass' and 'arse', which don't rhyme terribly well for the majority of English speakers (even in England). It all worked out to be a good Limerick though, IMHO :-)
What pleasure from sums we derive! Hidden text[irach & software] I didn't want to start the new year off on a pedantic note, but If you delete "up" and "Then" from your lines, respectively, they scan much more nicely