91Ó°ÊÓ

Some theoretical descriptions of during machines $T_1$ and $T_2$ must be defined at this point. The term "finite state transducer" (FST) is used to describe a device that has a finite number of states. $(Q,\underset{,}{∑}r,\mathrm{δ},q_0)$ tuple, where:

• The finite set of states is Q .

• The input alphabet is$\underset{}{∑}$.

• The output alphabet is r .

Some theoretical descriptions ofduring machines and must be defined at this point. The term

• The transition functiontakes a state and an input symbol and returns a state and an output symbol.

$\mathrm{δ}:Q×\underset{}{∑}→Q×r$

• The start state$q_0$.

The finite state transducer $T_1$ is formally defined by the $\left(\right\{q_{1,}{q}_2\},\{0,1,2\},\{0,1\},{\mathrm{δ}}_1,q_{1,})$ ., where the transition function is as follows:

The second FST is defined as . The transition function is given by: