The wrap~ object keeps the fractional part of audio. If the signal is 1.5, it will be wrapped to 0.5. Without wrapping, it would be clipped off.
The input audio signal from osc~ is multiplied by 2 so it is a 2*cos signal. The signal is thus between -2 and +2. The two clip~ objects pass either the positive part of the signal or negative part of the signal.
Each of the signal is wrapped. The positive is immediately wrapped. For the negative, we first adjust the sign so it is again positive. The wrap is done and then it is multiplied by -1, yielding back a negative signal. Finally, the positive and negative signals are summed. This summation is implied since two audio signals are flowing to only one audio channel.