Entering a new program

It is of course possible to input a program from scratch. It is not at all advisable to program whilst sitting in front of the computer screen, so we assume the reader to have written the following little program, that he now wishes to enter into the computer:


#elan103#

After starting the Elan Programming Environment, first focus on the name of the refinement which is to serve as the root of the program. Since it is rather hard to change the name of the root once it is chosen, we have to choose it with care.


#elan105#

The prompt tells us we have focussed successfully.


#elan107#

We now supply a definition for the root by means of the editor.


#elan109#

We type:


#elan111#

The prompt now tells us that the root is a refinement. Notice that we need not take particular pains to make a nice layout, because the <#113#>pretty printing<#113#> function of the show-command will standardize the layout anyway.


#elan114#