Answer:

 Axiomatic System (Postulate System)

           1.   Undefined terms/primitive terms

           2.   Defined terms

           3.   Axioms/postulates - accepted unproved statements

           4.   Theorems - proved statements

     An axiomatic system consists of some undefined terms (primitive terms) and a list of statements, called axioms or postulates, concerning the undefined terms. One obtains a mathematical theory by proving new statements, called theorems, using only the axioms (postulates), logic system, and previous theorems. Definitions are made in the process in order to be more concise.

     Most early Greeks made a distinction between axioms and postulates. Evidence exists that Euclid made the distinction that an axiom (common notion) is an assumption common to all sciences and that a postulate is an assumption peculiar to the particular science being studied. Now in modern times no distinction is made between the two; an axiom or postulate is an assumed statement.

     Usually an axiomatic system does not stand alone, but other systems are also assumed to hold.  For example, we will assume:

             1.   the real number system,

             2.   some set theory,

             3.   Aristotelian logic system, and

             4.   the English language.