We attempt to define the classical propositional logic by use of appropriate derivability conditions called Cn-definitions. The conditions characterize basic properties of propositional connectives.

Mastering mathematical symbols is essential for success in various fields, from science to technology. The article breaks down fundamental symbols like arithmetic operations, comparisons, variables, ...

We first extend Quine's method of eliminating the bound variables to first-order predicate logic with operation symbols ; then we give a device for eliminating also the free variables ; and finally we ...