Which idea dose the author mean to suggest by using the underlined phrase on page 5? plz help me

the audience knows that nora is intentionally failing to dance correctly, but helmer doesnt

. a function is a relation in which each input has only one output. in the relation , y is a function of x, because for each input x (1, 2, 3, or 0), there is only one output y. x is not a function of y, because the input y = 3 has multiple outputs: x = 1 and x = 2.

personaly i think it is a hope this !