Then (by completeness) it is provable from the wheel axioms.
Technically, the existence of uniform proofs for all provable goal formulas permits the search interpretation of provability.
Cyclic structures abound, and every sequent is provable.
This fact entails the possibility of considering different kinds of isomorphisms, in particular, provable isomorphisms as opposed to computable ones.
Finally, and most importantly, dealing with actual terms gives us an insight into provable isomorphisms that may be turned into computable ones.
Then we check that every provable proposition denotes the truth value 1 and hence that is not derivable.
One important fact about instances is that every instance of a provable typing statement is provable.
This means that uniform proofs must exist for all provable sequents.
