Since [3a] is immediately preceded by [2], the antecedent of “he” is probably (though not necessarily) “a farmer”, while “it” is anaphorically dependent on “a donkey”. At the DRS level, this is represented by equating the discourse referents v and w with x and y, respectively. These operations yield [4b], which is equivalent to [4c].  Either DRS is verified in a model M iff M features a farmer who chased and caught a donkey.