We will now modify one of the refinements of the program. We are focussed on <#365#>start horses<#365#> and give a show-command
We wish to change the <#368#>6<#368#> in the first line of the body of the refinement into <#369#>4<#369#>. To that end we give an edit-command
The same text appears, with on the status line
By means of the cursor keys (marked with arrows) we move the cursor to the right position, strike out the <#374#>6<#374#> by means of the <#375#>;SPMlt;DEL;SPMgt;<#375#>-key and insert a <#376#>4<#376#> instead. We then strike the <#377#>;SPMlt;RET;SPMgt;<#377#>-key to indicate that the modification is complete.
We now want to see what effect this modification has on the execution of the program. We first have to focus again on the root
We make use of the shorthand mechanism
By giving the execute-command we can verify that now only four horses take part in the race.