Show that the truth table given in Table 7.3 can

Show that the truth table given in Table 7.3 can

Show that the truth table given in Table 7.3 can be constructed by combining the following two steps:
(a) The message signal b(t) and PN signal c(t) are added modulo-2.
(b) Symbols 0 and 1 at the modulo-2 adder output are represented by phase shifts of 0 and 180 degrees, respectively.