Com how 3 vs 6 keystrokes michael 7 vs 15 keystrokes

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Unformatted text preview: state = "s"; foreach $c (@input) { $state = $transitiontable{$state}{$c}; } if ($state eq "y") { print "Accept\n"; } else { print "Reject\n"; } •  Example runs: perl fsm.prl a b a b Reject perl fsm.prl a a a b b Accept Finite State Automata (FSA) this is pseudo ­code not any real programming language Finite State Automata (FSA) •  prac6cal applica6ons • can be encoded and run efficiently on a computer • widely used – encode regular expressions – compress large dic6onaries – morphological analyzers • Different word forms, e.g. want, wanted, unwanted (suffixaNon/prefixaNon) • see chapter 3 of textbook • speech recognizers •  Markov models = FSA + probabiliNes • and much more … Finite State Automata (FSA) –  T9 text entry ( •  •  •  •  pre ­smart phone built in to older cellphones predicNve text entry for mobile messaging/data entry reduces the number of keystrokes for inpuyng words on a telephone keypad (8 keys) PredicNve typing/error correcNon from how: 3 vs. 6 keystrokes michael: 7 vs. 15 keystrokes ε ­transiNons •  jump from state to another state with the empty character –  ε ­transi6on (textbook) or λ ­transi6on –  no increase in expressive power •  examples > a b ε > a b ε > a b b what’s the equivalent without the ε ­transi5on?...
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This note was uploaded on 04/29/2012 for the course LING 438 taught by Professor Fong during the Fall '11 term at Arizona.

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