Similarly the theory recognizes as a separate element the pro-episode (patākāsthānaka), [636] an equivocal speech or situation which foreshadows an event whether near at hand or distant. The Nāṭyaçāstra distinguishes four kinds of equivoke. An ambiguous situation may result in bringing about the aim of the hero; thus in Act III of the Ratnāvalī, when Vatsa hastens to save Vāsavadattā, as he thinks, from hanging herself, he finds to his equal joy and surprise that he has rescued none other than Sāgarikā herself. [637] Or the equivocation may lie in words, whose sense the spectator alone grasps in its deeper application; thus in Act II of the Çakuntalā a voice behind the scene bids the female Cakravāka say farewell to her spouse, a command whose application to the case of the king and the heroine is immediately appreciated by the audience alone. Or the equivocation may be deliberately conveyed in the response of the actor, whose words apply not merely to the immediate matter in hand, but allude to the future; in the Veṇīsaṁhāra, Act II, Duryodhana is told of the mishap of the breaking of his standard by the fierce (bhīma) wind in words which presage his own fall, his thigh broken by Bhīma’s blow. Finally we may have a double entendre which later is destined to find a third application; in the Ratnāvalī Vatsa playfully suggests that his earnest gaze on the creeper, which has borne blossoms out of season, may cause jealousy in the queen; his words apply equally to a maiden, and in the sequel the queen is made furiously angry by his ardent gaze at Sāgarikā. The Daçarūpa contents itself with two species, equivocation of situation and deliberate equivocation of phrase, but there is general agreement that pro-episodes may be used in any part of the play and not merely in the first four junctures. Importance attaches to the conventions which enable the author to surmount difficulties inseparable from the dramatic form. [638] Normally, of course, the actors speak aloud (prakāçam), to be heard by all those on the stage as well as by the audience, but asides (svagatam, ātmagatam) are frequent, meant to be heard by the audience alone. If the need arises for making a remark to be heard by one actor only, it is made in the form of a confidence (apavāritam, apavārya), while a private conversation (janāntikam) is arranged by the actors holding up three fingers, the thumb and ring finger being curved inwards. Or, it is possible to avoid bringing on a person by speaking in the air (ākāçabhāṣita), pretending to hear the reply, and repeating it before answering it, while a similar purpose can be served by a voice from behind the scene. The number of Acts which a play should contain varies according to the nature of the drama; in the Nāṭaka the number must be at least five, and may be ten; in other cases one Act suffices. Normally the Acts are simply numbered; in some cases, as in that of the Mṛcchakaṭikā, names are given, doubtless not by the poet.