Gennaro (University of Cassino, Italy) Auletta 
Mechanical Logic in Three-Dimensional Space [PDF ebook] 

The book explores how build a mechanical inferences by making use of arithmetic operations on a string of numbers representing statements. In this way logic is reduced to a branch of the combinatory calculus. It covers the field of traditional logic by showing that any kind of inference can be mechanically reduced to three-variables and two-premise