Metamath Proof Explorer


Theorem inrab2

Description: Intersection with a restricted class abstraction. (Contributed by NM, 19-Nov-2007)

Ref Expression
Assertion inrab2 xA|φB=xAB|φ

Proof

Step Hyp Ref Expression
1 df-rab xA|φ=x|xAφ
2 abid1 B=x|xB
3 1 2 ineq12i xA|φB=x|xAφx|xB
4 df-rab xAB|φ=x|xABφ
5 inab x|xAφx|xB=x|xAφxB
6 elin xABxAxB
7 6 anbi1i xABφxAxBφ
8 an32 xAxBφxAφxB
9 7 8 bitri xABφxAφxB
10 9 abbii x|xABφ=x|xAφxB
11 5 10 eqtr4i x|xAφx|xB=x|xABφ
12 4 11 eqtr4i xAB|φ=x|xAφx|xB
13 3 12 eqtr4i xA|φB=xAB|φ