sentences:  He proposes a definition as shown in the boldface type that specifically identifies (renders identical) the notions of "machine computation" and "effectively calculable".This is a powerful expression.because "identicality" is actually an unequivocal statement of necessary and sufficient conditions, in other words there are no other contingencies to the identification" except what interpretation is given to the words "function", "machine", "computable", and "effectively calculable"