public <command> = [(tobi | tiago)] ( <ask_for_food> | <ask_for_bill_or_order>| yes | no | <stop> );
<ask_for_food> = [i would like to get | give me | bring me | can i have] [a | an] <food>
<ask_for_bill_or_order> = [please] [i would like to get | give me | bring me | can i have | i would like to | i would | let me | i will | i want to | set up] [the] <bill_or_order>
<ask_for_food> = [i would like to get | give me | bring me | can i have] [a | an] <food>;
<ask_for_bill_or_order> = [please] [i would like to get | give me | bring me | can i have | i would like to | i would | let me | i will | i want to | set up] [the] <bill_or_order>;