The European Network for Accessible Tourism (ENAT) is an organization focused on promoting accessible tourism across Europe. It aims to improve access to tourism experiences for people with disabilities, seniors, and other groups with specific access needs. ENAT works to raise awareness about the importance of accessibility in the tourism sector, encourages the implementation of accessible practices, and shares best practices among its members.

The Comparison Theorem is a fundamental result in real analysis, particularly in the study of improper integrals and series. It is often used to determine the convergence or divergence of a given integral or series by comparing it to another integral or series whose convergence is known. There are two main contexts in which the Comparison Theorem is applied: for integrals and for series.

The No Free Lunch (NFL) theorem is a concept in optimization and machine learning that states that there is no one-size-fits-all algorithm that is guaranteed to perform well on all possible problems. Instead, the performance of optimization algorithms is problem-dependent, meaning that an algorithm that works well for one class of problems may perform poorly on another.