| Samenvatting |
We are going to reconsider the existence property in
intuitionistic first order logic (IQC) with function symbols,
as presented in Dag Prawitz': "Natural Deduction, A Proof
Theoretical Study." That is, we will examine its formulation, and
try to give a constructive proof of the theorem. I mention in
particular the function symbols in IQC, because their presence
give rise to a new view on this property. Especially a tool from
resolution in automated theorem proving (Gallier [2]) will be
necessary for the tightening up of the property., |