premise: A record producer is planning the contents of a CD consisting of a sequence of exactly five instrumental pieces—Reciprocity, Salammbo, Trapezoid, Vancouver, and Wisteria. To create and sustain certain moods, the sequence of pieces will satisfy the following constraints: Salammbo must be earlier than Vancouver. Trapezoid must either be earlier than both Reciprocity and Salammbo or after than both Reciprocity and Salammbo. Wisteria must either be earlier than both Reciprocity and Trapezoid or after than both Reciprocity and Trapezoid. If Trapezoid is the second piece on the CD, then which one of the following could be true?
hypothesis: Reciprocity is the first piece on the CD.