Metamath Proof Explorer


Theorem ineq2

Description: Equality theorem for intersection of two classes. (Contributed by NM, 26-Dec-1993)

Ref Expression
Assertion ineq2 ⊢ A = B → C ∩ A = C ∩ B

Proof

Step Hyp Ref Expression
1 ineq1 ⊢ A = B → A ∩ C = B ∩ C
2 incom ⊢ C ∩ A = A ∩ C
3 incom ⊢ C ∩ B = B ∩ C
4 1 2 3 3eqtr4g ⊢ A = B → C ∩ A = C ∩ B