An Unabridged, Unaltered Printing Of Volume I of III: Part I - MATHEMATICAL LOGIC - The Theory Of Deduction - Theory Of Apparent Variables - Classes And Relations - Logic And Relations - Products And Sums Of Classes - Part II - PROLEGOMENA TO CARDINAL ARITHMETIC - Unit Classes And Couples - Sub-Classes, Sub-Relations, And Relative Types - One-Many, Many-One, And One-One Relations - Selections - Inductive Relations