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b(standard)h(input/output)f(and)h(\223pipe\224)f(mechanism.)29 b(Thus,)21 b(a)g(class-)1975 2752 y(based)d(N-gram)g(model)f(can)h(be)f(trained,)h(pruned,)g(e)o(xpanded)h(into)e(a)g(w)o(ord)1975 2838 y(trigram)j(model,)g(and)h(interpolated)g(with)e(another)i(model)f(using)h(the)f(fol-)1975 2925 y(lo)n(wing)g(pipeline)f(\(some)h(options)f(ha)o(v)o(e)g(been)h(omitted)f(to)g(sa)o(v)o(e)g(space\):)1975 3118 y Fh(replace-words-with-classes)41b(TRAINDATA)i(|)i(\\)1975 3205 y(ngram-count)e(-text)h(-)h(-lm)f(-)h(|)g(\\)1975 3292 y(ngram)f(-lm)h(-)f(-prune)g(1e-5)g(-write-lm)g(-)g(|)h(\\)1975 3378 y(ngram)f(-lm)h(-)f(-expand-classes)f(3)h(-write-lm)g(-)g(|)h(\\)1975 3465 y(ngram)f(-lm)h(-)f(-mix-lm)g(LM2)g(-write-lm)g(MIXLM)1975 3678 y Fl(4.3.)h(Helpers)19 b(and)f(wrappers)19753816 y Fj(Miscellaneous)39 b(other)e(tools)g(are)g(implemented)g(in)g(ga)o(wk)g(and)h(shell)1975 3903 y(scripts,)64 b(either)55b(because)h(the)o(y)g(in)m(v)o(olv)o(e)f(simple)g(te)o(xt)g(manipula-)1975 3990 y(tions)g(that)f(are)g(more)h(con)m(v)o(eniently)h(done)g(this)e(w)o(ay)h(\(such)g(as)1975 4077 y Fh(replace-words-with-classes)20 b Fj(in)25 b(the)g(e)o(xample)g(abo)o(v)o(e\),)i(or)19754163 y(because)20 b(the)o(y)e(only)h(require)f(a)g(wrapper)h(that)f(combines)h(the)f(basic)h(tools.)1975 4250 y(An)30 b(e)o(xample)h(of)f(the)g(latter)f(is)h Fh(change-lm-vocab)p Fj(,)f(a)h(script)g(that)19754337 y(modi\002es)i(the)g(v)o(ocab)o(ulary)g(of)f(an)h(e)o(xisting)g

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