protasis

{{For|the concept of protasis in linguistics|Conditional sentence}}

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In drama, a protasis is the introductory part of a play, usually its first act. The term was coined by the fourth-century Roman grammarian Aelius Donatus. He defined a play as being made up of three separate parts, the other two being epitasis and catastrophe. In modern dramatic theory the term dramatic arc has substantially the same meaning,{{Cite web|url=https://makingmusic.ableton.com/dramatic-arc|title = Dramatic Arc}} though with slightly different divisions.