Metamath Proof Explorer


Theorem inteqd

Description: Equality deduction for class intersection. (Contributed by NM, 2-Sep-2003)

Ref Expression
Hypothesis inteqd.1 φA=B
Assertion inteqd φA=B

Proof

Step Hyp Ref Expression
1 inteqd.1 φA=B
2 inteq A=BA=B
3 1 2 syl φA=B