**Symbols**

1. (Belongs to)

2. (Does not belongs to)

3. :or (Such that)

4. < (Less than)

5. > (Greater than)

6. (And)

7. V (or)

8. (For every or For all)

9. (Implies that)

10. (Is implied by)

11. (If and only if) or (Implies and is implied by)

12. (Is a subset of)

13. (Is not a subset of)

14. (Is a super set of or Is contains)

15. (Is a proper subset of or Is contained in)

16. ⊄ (Is not a proper subset of or, Is not contained in)

17. (There exist)

18. (Union of sets)

19. (Intersection of sets)

20. U (universal set )

21. Congruent