The authors developed some time ago a RBES devoted to preparing personalized menus at
restaurants according to the allergies, religious constraints, likes and other diet requirements
as well as products availability. A first version was presented at the "Applications of Computer
Algebra 2015" (ACA'2015) conference and an improved version to the "5th European
Seminar on Computing" (ESCO2016). Preparing personalized menus can be specially
important when traveling abroad and facing unknown dishes in a menu. Some restaurants
include icons in their menu regarding their adequateness for celiacs or vegetarians and vegans,
but this is not always a complete information, as it doesn't consider, for instance, personal
dislikes or uncommon allergies. The tool previously developed can obtain, using logic deduction,
a personalized menu for each customer, according to the precise recipes of the restaurant
and taking into account the data given by the customer and the ingredients out of stock (if
any). Now a new approach has been followed, using functions and set operations and the
speed has been increased by three orders of magnitude, allowing to deal with huge menus
instantly. Both approaches have been implemented on the computer algebra system Maple
and are exemplified using the same recipes in order to compare their performances.