计时操作 "b" to "b" plus .1 left brace, "c" greater than 0 , right brace , "a" to "b" left brace, "b" less than 32 , right brace , "a" to "b" minus 32 left brace, 48 greater than "b" greater than 32 , right brace , "c" to "c" minus 1 left brace, "b" equals 32 , "b" equals 48 , right brace , "a" to 0 left brace, "c" less than or equal to 0 , right braceb→b+.1c>0,a→bb<32,a→b−3248>b>32,c→c−1b=32,b=48,a→0c≤0
