Re: Value

ram_at_zedat.fu-berlin.de (Stefan Ram) writes:
>A value in mathematics or computer science is any object or
>entity.

  This notion is so wide that it might help to explain,   what is /not/ a value.

  A simple model for this is the common mathematical   language of terms and formulas.

  Usually, a term is not a value, a formula is not a   value and the meaning of a formula is not a value.   (In metamathematics, terms and formulas might become   values, but usually they are not.)

  What is a value, is the meaning of a term.   A term refers to a value, it denotes a value.

  In a simple procedural programming language, there   are »expressions« and »statements« instead of   »terms« and »formulas«. There, a value is what is   denoted by a (non-void) expression.

  However, one must be careful, when defining a value   as »what an expression denotes«, because this might   create a circular definition, when an expression is   being defined as a means to denote a value. Therefore,   I have chosen to give a definition independent of   expressions in my preceding post.

  In mathematical logic, a formula uses a relation symbol to   assert a relation between certain entities. These entities   are the values. So, anything than can have a relation   to something else is a value. Therefore, I said, that   a value is what one can make an assertion about. Received on Sat Feb 23 2008 - 22:49:35 CET