[plt-scheme] Checking a result with "Intermediate plus Lambda" student Language

[Jean-Paul ROY]

I am moving from 372 to 399.xx. "Intermediate plus Lambda" student  
language

How can I test a function when the result is not yet known (say with  
random), through a polite message :

The value of the dice is 4

I tried a Scheme splice box but the students don't know lists and  
quasiquotation yet, and the above message within a list seems not so  
pretty...

Do I miss a "check without already known result" primitive ?

    -jpr