Let gettoken() be a function that returns the next token in the input. if we call it repeatedly it will return one token after another. when all the input is consumed, gettoken() returns eof (end of file). assume that longest prefix-matching rule is used by gettoken() and ties are broken in favor of the regular expression listed first.

Read the excerpt from “strychnine in the soup,” in which mr. mulliner explains the ending of a mystery novel to a bar patron who is anxious to know the conclusion of the story. “the plumber forgot his snake and had to go back for it,” explained mr. mulliner. ‘‘i trust that this revelation will prove sedative.” “i feel a new man,” said the draught stout. “i’d have lain awake worrying about that murder all night.” explain how a student who did not know the meaning of sedative could infer its definition?