@startuml
start
:User inputs 'findbook Harry Potter';

'Since the beta syntax does not support placing the condition outside the
'diamond we place it as the true branch instead.

if () then ([valid input])
    if () then ([list contains books named 'Harry Potter'])
        :SmartLib shows list of books that
                 contains the keyword 'Harry';
    else ([else])
        :SmartLib shows an empty list;
    endif
else ([else])
    :Print "Unknown Command";
endif
stop
@enduml

