Scrabble?! REFLEXIVELY

Definitions of REFLEXIVELY in various dictionaries:

A set has closure under an operation if performance of that operation on members of the set always produces a member of the same set; in this case we also say that the set is closed under the operation. For example, the positive integers are closed under addition, but not under subtraction: 1 − 2 {\displaystyle 1-2} is not a positive integer even though both 1 and 2 are positive integers. Another example is the set containing only zero, which is closed under addition, subtraction and multiplication (because 0 + 0 = 0 {\displaystyle 0+0=0} , 0 − 0 = 0 {\displaystyle 0-0=0} , and 0 × 0 = 0 {\displaystyle 0\times {0}=0} ). Similarly, a set is said to be closed under a collection of operations if it is closed under each of the operations individually.