The type of the identifier generated

The type of the generator

init () returns a new generator

get_fresh_id gen returnds a pair (id,gen') where id is a fresh id and gen' a new generator that knows id was already generated.

eq id1 id2 returns true if id1=id2 and fase otherwise.

compare id1 id2 returns an integer which is 0 if id1=id2, negative of id1 is less than id2 and positive otherwise.

IdMap implements maps whose keys are identifiers

Table implements correspondance tables with the current identifiers