Does the subject want to ask "what is the violation of differential pricing in gyms?" Discriminatory pricing, monopolistic behavior, unfair competition.

1. Discriminatory pricing: The basis of differential pricing is related to specific groups whose race, sex, religion and nationality are protected by law, and it is suspected of violating anti-discrimination laws or anti-discrimination clauses.

2. Monopolistic behavior: The implementation of differential pricing by monopolistic forces or market manipulators has a negative impact on fair competition in the market and violates the anti-monopoly law.

3. Unfair competition: Differentiated pricing leads to false or misleading price information, leading to consumers being deceived or misled, which violates the Anti-Unfair Competition Law.