Article XX provides that a student, apprentice, or business trainee temporarily present…

Contracting State for the purpose of his full-time education or training is exempt from tax in that State with respect to amounts received from outside that State for the purpose of his maintenance, education, or training, if the individual is or was a resident of the other Contracting State immediately before visiting the first-mentioned State. There is no limitation on the number of years or the amount of income to which the exemption applies.

The Convention does not contain provisions relating specifically to professors and teachers. Teachers are treated under the Convention pursuant to the rules established in Articles XIV (Independent Personal Services) and XV (Dependent Personal Services), in the same manner as other persons performing services. In Article VIII A of the 1942 Convention there is a 2-year exemption in the Contracting State of source in the case of a professor or teacher who is a resident of the other Contracting State.