Preferably, {HEAD ~ the conductive elements} have {TAIL ~ the form} of a conductive yarn with one or more of: a core of insulating material, an electrical resistance heating element, e.g., about the core, and a sheath material surrounding the electrical resistance heating element  
have
Preferably , { HEAD ~ the conductive elements } have { TAIL ~ the form } of a conductive yarn with one or more of : a core of insulating material , an electrical resistance heating element , e.g. , about the core , and a sheath material surrounding the electrical resistance heating element
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL 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 OTH OTH OTH OTH OTH OTH OTH OTH