I don't know, probably can't really know. Maybe someone with more internal information could provide a more definite answer, but likely not. It was simply an accident that I happened to stumble onto this solution. I have seen a few times in the past where WA seemed to treat some names differently from others. I would watch for x,y,z if you are not expecting those to be generic numeric values. Watch for e,i,n,m. You might watch for other one or two or three character names that tend to have an agreed on definition or use in mathematics or elsewhere. I'm really glad that it worked out for you.
