Metamath Proof Explorer


Theorem ineq2d

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

Ref Expression
Hypothesis ineq1d.1 φA=B
Assertion ineq2d φCA=CB

Proof

Step Hyp Ref Expression
1 ineq1d.1 φA=B
2 ineq2 A=BCA=CB
3 1 2 syl φCA=CB