Original: A Gödel numbering can be interpreted as an encodingA prior usage of such an encoding can be found in , for example , Ludwig Wittgenstein (/O1921/O) , Tractatus Logico-Philosophicus proposition 5.101 .
Simplified: If f is the Gödel mapping and if formula C can be derived from formulas A and B through an inference rule r , i.e.