.PS boxwid:=1.5; boxht:=0.75 B00: box boxwid:=1.5; boxht:=0.75 B01: box with .n at B00.s circle at B01.c rad 0.1 filled arrow from B01.c right boxwid/2 + 0.2 boxwid:=2; boxht:=0.75 N0100: box "becomes" "9" "134720492145(17)" boxwid:=1.5; boxht:=0.75 B02: box with .n at B01.s circle at B02.c rad 0.1 filled arrow from B02.c right boxwid/2 + 0.2 boxwid:=2; boxht:=0.75 N0200: box "necessary" "10" "164114526854434(2)" boxwid:=1.5; boxht:=0.75 B03: box with .n at B02.s circle at B03.c rad 0.1 filled arrow from B03.c right boxwid/2 + 0.2 boxwid:=2; boxht:=0.75 N0300: box "human" "6" "131651875(3)" boxwid:=1.5; boxht:=0.75 B04: box with .n at B03.s boxwid:=1.5; boxht:=0.75 B05: box with .n at B04.s boxwid:=1.5; boxht:=0.75 B06: box with .n at B05.s circle at B06.c rad 0.1 filled arrow from B06.c right boxwid/2 + 0.2 boxwid:=2; boxht:=0.75 N0600: box "in" "2" "3686(6)" boxwid:=2; boxht:=0.75 N0601: box "people" "13" "4647902198(22)" boxwid:=2; boxht:=0.75 N0602: box "course" "4" "4135697990(6)" boxwid:=1.5; boxht:=0.75 B07: box with .n at B06.s boxwid:=1.5; boxht:=0.75 B08: box with .n at B07.s circle at B08.c rad 0.1 filled arrow from B08.c right boxwid/2 + 0.2 boxwid:=2; boxht:=0.75 N0800: box "When" "1" "3344568(24)" boxwid:=2; boxht:=0.75 N0801: box "one" "12" "128504(24)" boxwid:=1.5; boxht:=0.75 B09: box with .n at B08.s circle at B09.c rad 0.1 filled arrow from B09.c right boxwid/2 + 0.2 boxwid:=2; boxht:=0.75 N0900: box "events" "7" "4224378201(25)" boxwid:=1.5; boxht:=0.75 B10: box with .n at B09.s circle at B10.c rad 0.1 filled arrow from B10.c right boxwid/2 + 0.2 boxwid:=2; boxht:=0.75 N1000: box "of" "5" "3882(10)" boxwid:=1.5; boxht:=0.75 B11: box with .n at B10.s circle at B11.c rad 0.1 filled arrow from B11.c right boxwid/2 + 0.2 boxwid:=2; boxht:=0.75 N1100: box "the" "3" "133915(27)" boxwid:=1.5; boxht:=0.75 B12: box with .n at B11.s circle at B12.c rad 0.1 filled arrow from B12.c right boxwid/2 + 0.2 boxwid:=2; boxht:=0.75 N1200: box "it" "8" "3692(12)" boxwid:=2; boxht:=0.75 N1201: box "for" "11" "118444(12)" boxwid:=1.5; boxht:=0.75 B13: box with .n at B12.s boxwid:=1.5; boxht:=0.75 B14: box with .n at B13.s boxwid:=1.5; boxht:=0.75 B15: box with .n at B14.s .PE