*   A computer program is a specific, finite list 
    of instructions for solving a problem.

*   a programming environment is software that
    provides a convenient setting for developing
    these lists of instructions;

    An IDE -- integrated development environment --
    is a fancy programming environment...

    DrRacket is an IDE, a programming environment;

*   what is an EXPRESSION?
    ...is something that has a VALUE in a 
       programming language

    *   a SIMPLE EXPRESSION is a single value,
        and in a programming language you have
        to type it in a special way so the
	computer can  "understand" it;

*   SYNTAX: the rules for typing something in
    a programming language, so the computer can
    understand it;

    SEMANTICS: the meaning of an expression or
    statement

*   An expression in racket has a TYPE
    (a DATA type)
    ...the syntax for a simple expression
       depends on its type;