Mocquereau with original rsigns and neumes, no difficulty with this very formulaic antiphon

This is not so straightforward, because while this typical melody has fully syllabic instances, the merging of notes into a clivis does not always lead to cl-, sometimes cl (but into a pes, it always leads to peS) => elected to use cl- on the first fusion, cl on the second, cl- on the third.

See e.g. the A/ Potens in terra and its companion alleluia antiphon, http://www.omnigreg.at/wiki/doku.php?id=ant:0950