 Despite the fact that algebraic fibring is suitable for combining an ample class of logic systems, some kinds of logics, namely substructural logics such as linear logic, and logics equipped with a nondeterministic semantics, lie outside the scope of this combination method. Moreover, at the semantical level, algebraic fibring, by its own nature, does not make possible to keep representatives of all the models of the original logics (which leads to the collapsing problem of fibring, see  section 5).