Metamath Proof Explorer


Theorem ineq1d

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

Ref Expression
Hypothesis ineq1d.1 φ A = B
Assertion ineq1d φ A C = B C

Proof

Step Hyp Ref Expression
1 ineq1d.1 φ A = B
2 ineq1 A = B A C = B C
3 1 2 syl φ A C = B C