(2) An unaccented weak vowel between two other vowels prevents synalœpha of these latter; thus, comercio y agricultura, in which the io is kept apart from the a by the y, which itself forms a diphthong with the a; so also Sevilla ú Oviedo with the a in one syllable and the uo in another. Some writers have violated this rule, but most have observed it.
(3) ó prevents synalœpha and forms a syllable with the following vowel; Lupercio de Argensola:
El orbe escucha atónito ó atento.
(4) The conjunction é generally prevents synalœpha; Lupercio de Argensola:
Pues he de retratarme, dónde ó cómo
Me pueda yo estar viendo é imitando.
Synalœpha is not wholly inadmissible.
(5) Two similar contiguous vowels form synalœpha, and the sound is a single prolonged one: el voluble elemento.
Three similar contiguous vowels may form synalœpha, but the combination is a harsh one; as in Maury:
No su palanca á Arquímedes le diera.