The S bent line may include, instead of or in addition to circular arc curved lines, for example, an elliptic arc curved line, sinusoidal curved line, {HEAD ~ exponential curved line} and a combination of {TAIL ~ any curved and straight lines} 
The S bent line may include , instead of or in addition to circular arc curved lines , for example , an elliptic arc curved line , sinusoidal curved line , { HEAD ~ exponential curved line } and a combination of { TAIL ~ any curved and straight lines }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL