文章与日志

what is mathematics?

--------------------------------------------------------------------------------

The Detail of This Chapter.pdf

--------------------------------------------------------------------------------

the first event: 1, 2, 3,...

then, we know that counting means +1

the first principle: no more, nor less.
addition, subtraction, multiplication, division

subtraction lead to 0 and negatives

division lead to fraction

the closeness of operation=>the set of number: natural number, integral number, rational number.

infinity.

【complete induction】

how to denote number? base and power

how to solve algebraic equation?

the complete of order=>real number set

the second principle: completeness
any two elements of set R, a>b, or b>a,