A causal all-pass system Hap(z) has input x[n] and output y[n]. (a) If x[n] is a re...

A causal all-pass system Hap(z) has input x[n] and output y[n].

(a) If x[n] is a real minimum-phase sequence (which also implies that x[n] = 0 forn < 0), using Eq. (5.108), show that

(b) Show that Eq. (P5.73-1) holds even if x[n] is not minimum phase, but is zero for n < 0.