Moving Light Clock

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  \put(92,11){$x_L$}
  \put(6,10){$\underbrace{\rule{4cm}{0cm}}$}
  \put(26,5){\makebox(0,0){$v\cdot\Delta t_L$}}
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  \put(46,32){\circle*{2}}
  \put(46,12){\line(0,1){20}}
  \put(6,12){\vector(2,1){39}}  
  \put(18,25){$c\cdot\Delta t_L$}
  \put(46,32){\vector(2,-1){39}}
  \put(46,22){\line(2,-1){8}} 
  \put(54.5,16){$h=c\cdot\Delta\tau$}
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