Write a transducer that deals with the y rule, in analogy to the transducer in Figure 3.17 in the Speech and Language Processing (Daniel Jurafsky) book, that deals with e insertion given below -

Your transducer must model the following facts:

a y at the end of the root of a noun, if preceded by a consonant, is changed to ie before adding the s of the plural;

a y at the end of the root of a verb, if preceded by a consonant, is changed to ie before adding the s of the present, third person singular

a y at the end of the root of a verb, if preceded by a consonant, is changed to ie before adding the d of the simple past / past participle

if the y is preceded by a vowel, the y is unchanged: for example, the plural of decoy is decoys not decoies; the past of decay is decayed not decaied.

Note that cases 1-3 are simplifications of the true facts, but we will use them for this exercise: to be precise, the e should be dealt with separately; in the case of the simple past, a better model would change y to i and add ed, the true ending for the simple past (by saying that the past morpheme is simply a d, then we have to deal with decay by rewriting d as ed).

Example facts, including the intermediate form, are shown in the following table:

Root - Intermediate - Surface

reply - replys# - replies

fry - frys# - fries

heresy - heresys# - heresies

apply - applyd# - applied

try - tryd# - tried

verify - verifys# - verifies

decoy - decoys# - decoys

decay - decayd# - decayed

Your FST should be as general as possible; namely, you should capture the rules, not the individual words. Of course, a word like rye should not be changed to rIESe.

Simplifications: 1. You can assume you have two classes of letters, vowels and consonants, neither of which includes y. 2. You can assume that a word starts with at least a consonant or a vowel, before a y is seen. 3. Dont worry about adjectives ending in y, from my, to flimsy, to many others.

other other Z,s,X A: A.E Z,S,X q1 93 94 2 othe Z, X #, other Figure 3.17The transducer for the E-insertion rule of (3.4), extended from a similar transducer in Antworth mbol from the surface string: this can be done either by interpreting the symbol # as the pair , or by postprocessing the output to remove word boundaries. (1990), we additionally need to delete the # sy