The slide element has {HEAD ~ a tongue} upwardly extending from the front end thereof and provided with {TAIL ~ an inclined outer surface} which abuts the front end of the cover member 
The slide element has { HEAD ~ a tongue } upwardly extending from the front end thereof and provided with { TAIL ~ an inclined outer surface } which abuts the front end of the cover member
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH