1.2.3.3 Principia Mathematica



Russell decided to tackle the problem of the origins of mathematics
. He and Whitehead were convinced that it was founded on Logic.
After twenty years hard work, they produced a book
called Principia Mathematica
which built the whole of mathematics from a set of basic axioms and the rules of logic


A proof from this book has been reproduced overleaf.
What proof do you think this is
.