[AFRICANUS libro septimo quaestionum. ] §4.6.43.prSi quis stipulatus sit in annos singulos, quoad in Italia esset uel ipse uel promissor, et alteruter rei publicae causa abesse coeperit, officium praetoris est introducere utilem actionem.
[AFRICANUS, Questions, Book VII] If anyone has stipulated for annual payments so long as either he himself or the promisor should be in Italy, and either of them begins to be absent on public service, it is the duty of the praetor to grant an equitable action.
eadem dicemus, et si ita concepta stipulatio fuerit: 'si quinquennio proximo Romae fuerit', uel ita: 'si Romae non fuerit, centum dare spondes?'
We shall say the same even if the stipulation has been formulated in this way: 'if he shall have been in Rome for the next five years,' or in this way: 'if he shall not have been in Rome, do you promise to give one hundred?'