CWNA 106 Deluxe Study Guide Typo in Chapter 2 Pg.23

Phase-Shift Keying - "PSK is can be a state transition technique, where the change of phase can represent a 0 bit and the lack of a phase change can represent a 1 bit, or vice versa."

Should it be, "PSK is a state...." or, "PSK can be a state....." or, "PSK is/can be a state..."

everything points to "PSK is a state..." But I'm not an expert and I doubt it's a big deal but I figured I'd throw it in.