Having trouble saying this in Lojban: The general rule for pro-sumti is that if saying it again gets you the same sumti, then {ri} doesn't capture it. If you want the same referent, just use the same pro-sumti again. So you {ri} skips backwards over those. But it does grab pro-sumti which could/would be different if repeated literally ({ma}, {ce'u}, {t[iau]}, maybe a few others I'm overlooking at the moment).
From IRC logs: