Which operator must be defined in order to implement the Comparable module?

To implement the Comparable module in Ruby, you must define the <=> operator, also known as the spaceship operator. This operator is essential because it compares the object in which it's defined to another object, returning -1, 0, or 1 depending on whether the first object is less than, equal to, or greater than the second object[1][3]. This single method implementation enables the use of other comparison methods like <, <=, ==, >=, and > provided by the Comparable module[3].

Citations:
[1] https://dev.to/baweaver/understanding-ruby-comparable-34ki
[2] https://...