In this case, we are going to write a spec.

　　Suppose there is a English-speaking alien, and he is unable to tie his shoes. So we have to write a short, simple spec to show him how to tie the shoes. We can also add some pictures in the spec.

Spec: How To Tie Your Shoes

　　This method is divided into 11 steps. 

　　Step 1: Make a cross. 

　　Step 2: Turn around. 

　　Step 3: Pass through and pull. 

　　Step 4: Half complete. 

　　Step 5: Fold laces into double-strand. 

　　Step 6: Make the second cross. 

　　Step 7: Turn around. 

　　Step 8: Pass through and pull. 

　　Step 9: Pull and finish. 

　　Now, it is done. And you can tidy up your shoelaces.