Mathematical structure and Multiple choice

     A sonnet repeats the iambic rhythm of the heart beat (da-DUM, da-DUM, . . .) with a line length corresponding to a typical breath (5 heartbeats); it thus seems easy to internalize the numerical structure that guides such a poem. 
     A decision tree offers a very different choice of mathematical structure for a poem -- displaying for a reader different choices among stanzas.  Originally proposed to the OULIPO by founder Francois Le Lionnais, and referred to as a multiple-choice narrative, such a structure allows readers of a poem to choose among subsequent events. Instead of reading the poem vertically, we may jump about, choosing the sequence we want to read.