Definitions

• A definition is a special kind of expression of the form

      (define name expression)   

• The value of expression is determined and it is given the name name

• Examples:

      (define x 147273)
      (define y -98327)  

• You can use the defined names in other expressions:

      (+ (* x x)
         (* x y)
         (* y y))  

• expression can be an application:

      (define result (+ (* x x)
                        (* x y)
                        (* y y)))
  

  Now result is a name for 16,876,623,187