Some linear Twelf code on the connection between sequent calculus
and linear natural deduction.

ill.llf  ---  Propositions of intuitionistic linear logic
nd.llf   ---  Natural deduction for ILL
seq.llf  ---  Sequent calculus for ILL
local.llf --- Local reductions and expansion for natural deductions
ie.llf   ---  Annotation of natural deductions in introduction and
              eliminations
sound.llf  ---  Translation of sequent derivations to natural deductions
complete.lff ---  Translation of natural deductions to sequent derivations

The translations in the last two do not take advantage of normal
forms.  Therefore, they do not exhibit the connection between normal
natural deductions and cut-free sequent derivations (which is left
as an exercise).
