Metamath Proof Explorer


Theorem ineq2d

Description: Equality deduction for intersection of two classes. (Contributed by NM, 10-Apr-1994)

Ref Expression
Hypothesis ineq1d.1 ⊢ φ → A = B
Assertion ineq2d ⊢ φ → C ∩ A = C ∩ B

Proof

Step Hyp Ref Expression
1 ineq1d.1 ⊢ φ → A = B
2 ineq2 ⊢ A = B → C ∩ A = C ∩ B
3 1 2 syl ⊢ φ → C ∩ A = C ∩ B