Reflection

"Reflection" in math mainly refers to the mirror symmetry operation in geometric transformations, which means flipping points, lines, or shapes across a line (for plane reflection) or a point (for central symmetry) to create a congruent mirror image; this is a type of rigid (isometric) transformation. Also, in mathematical logic, the "reflection principle" is a deep concept in set theory about the consistency between a formal system and the models of its finite subsystems.