\unitlength 0.50mm \special{em:linewidth 0.4pt} \linethickness{0.4pt} \begin{picture}(130.00,97.00) \emline{0.00}{90.00}{1}{130.00}{90.00}{2} \emline{10.00}{90.00}{3}{8.00}{91.00}{4} \emline{10.00}{90.00}{5}{8.00}{89.00}{6} \emline{18.00}{91.00}{7}{20.00}{90.00}{8} \emline{20.00}{90.00}{9}{18.00}{89.00}{10} \emline{30.00}{90.00}{11}{28.00}{91.00}{12} \emline{30.00}{90.00}{13}{28.00}{89.00}{14} \emline{38.00}{91.00}{15}{40.04}{90.04}{16} \emline{40.04}{90.04}{17}{38.03}{89.04}{18} \emline{48.00}{91.00}{19}{49.98}{90.04}{20} \emline{49.98}{90.04}{21}{47.97}{89.04}{22} \emline{58.00}{91.00}{23}{59.99}{90.00}{24} \emline{59.99}{90.00}{25}{57.97}{89.08}{26} \emline{68.00}{91.00}{27}{69.93}{90.00}{28} \emline{69.93}{90.00}{29}{67.91}{89.08}{30} \emline{78.00}{91.00}{31}{80.06}{90.00}{32} \emline{80.06}{90.00}{33}{78.03}{89.08}{34} \emline{88.00}{91.00}{35}{90.00}{90.00}{36} \emline{90.00}{90.00}{37}{87.97}{89.08}{38} \emline{98.00}{91.00}{39}{99.94}{90.00}{40} \emline{99.94}{90.00}{41}{97.92}{89.08}{42} \emline{108.00}{91.00}{43}{110.07}{90.00}{44} \emline{110.07}{90.00}{45}{108.04}{89.08}{46} \emline{118.00}{91.00}{47}{120.01}{90.00}{48} \emline{120.01}{90.00}{49}{117.98}{89.08}{50} \emline{128.00}{91.00}{51}{129.95}{90.00}{52} \emline{129.95}{90.00}{53}{127.92}{89.08}{54} \emline{45.00}{51.00}{55}{47.06}{50.00}{56} \emline{47.06}{50.00}{57}{45.03}{49.08}{58} \emline{55.00}{51.00}{59}{57.00}{50.00}{60} \emline{57.00}{50.00}{61}{54.97}{49.08}{62} \emline{65.00}{51.00}{63}{66.94}{50.00}{64} \emline{66.94}{50.00}{65}{64.92}{49.08}{66} \emline{75.00}{51.00}{67}{77.07}{50.00}{68} \emline{77.07}{50.00}{69}{75.04}{49.08}{70} \emline{85.00}{51.00}{71}{87.01}{50.00}{72} \emline{87.01}{50.00}{73}{84.98}{49.08}{74} \emline{95.00}{51.00}{75}{96.95}{50.00}{76} \emline{96.95}{50.00}{77}{94.92}{49.08}{78} \put(97.00,50.00){\vector(-4,3){53.00}} \put(44.00,89.67){\vector(-1,-4){10.00}} \emline{34.00}{50.00}{79}{97.00}{50.00}{80} \put(97.00,50.00){\vector(-1,4){10.00}} \put(87.00,90.00){\vector(-4,-3){53.00}} \put(65.00,52.00){\makebox(0,0)[cb]{first subroutine}} \put(2.00,92.00){\makebox(0,0)[lb]{main program sequence}} \put(45.00,87.00){\makebox(0,0)[ct]{$a$}} \put(85.00,87.00){\makebox(0,0)[ct]{$b$}} \put(34.00,47.50){\makebox(0,0)[ct]{$x$}} \put(97.00,47.50){\makebox(0,0)[ct]{$y$}} \emline{61.00}{11.00}{81}{63.06}{10.00}{82} \emline{63.06}{10.00}{83}{61.03}{9.08}{84} \emline{71.00}{11.00}{85}{73.00}{10.00}{86} \emline{73.00}{10.00}{87}{70.97}{9.08}{88} \emline{81.00}{11.00}{89}{82.94}{10.00}{90} \emline{82.94}{10.00}{91}{80.92}{9.08}{92} \emline{91.00}{11.00}{93}{93.07}{10.00}{94} \emline{93.07}{10.00}{95}{91.04}{9.08}{96} \emline{101.00}{11.00}{97}{103.01}{10.00}{98} \emline{103.01}{10.00}{99}{100.98}{9.08}{100} \emline{111.00}{11.00}{101}{112.95}{10.00}{102} \emline{112.95}{10.00}{103}{110.92}{9.08}{104} \put(113.00,10.00){\vector(-4,3){53.00}} \put(60.00,49.67){\vector(-1,-4){10.00}} \emline{50.00}{10.00}{105}{113.00}{10.00}{106} \put(81.00,7.00){\makebox(0,0)[ct]{nested subroutine}} \put(61.00,47.00){\makebox(0,0)[ct]{$c$}} \put(50.00,7.50){\makebox(0,0)[ct]{$u$}} \put(113.00,7.50){\makebox(0,0)[ct]{$v$}} \end{picture}