Metamath Proof Explorer


Theorem difrab2

Description: Difference of two restricted class abstractions. Compare with difrab . (Contributed by Thierry Arnoux, 3-Jan-2022)

Ref Expression
Assertion difrab2 xA|φxB|φ=xAB|φ

Proof

Step Hyp Ref Expression
1 nfrab1 _xxA|φ
2 nfrab1 _xxB|φ
3 1 2 nfdif _xxA|φxB|φ
4 nfrab1 _xxAB|φ
5 eldif xABxA¬xB
6 5 anbi1i xABφxA¬xBφ
7 andi φ¬xB¬φφ¬xBφ¬φ
8 pm3.24 ¬φ¬φ
9 8 biorfi φ¬xBφ¬xBφ¬φ
10 ancom φ¬xB¬xBφ
11 7 9 10 3bitr2i φ¬xB¬φ¬xBφ
12 11 anbi2i xAφ¬xB¬φxA¬xBφ
13 anass xAφ¬xB¬φxAφ¬xB¬φ
14 anass xA¬xBφxA¬xBφ
15 12 13 14 3bitr4i xAφ¬xB¬φxA¬xBφ
16 6 15 bitr4i xABφxAφ¬xB¬φ
17 rabid xxAB|φxABφ
18 eldif xxA|φxB|φxxA|φ¬xxB|φ
19 rabid xxA|φxAφ
20 ianor ¬xBφ¬xB¬φ
21 rabid xxB|φxBφ
22 20 21 xchnxbir ¬xxB|φ¬xB¬φ
23 19 22 anbi12i xxA|φ¬xxB|φxAφ¬xB¬φ
24 18 23 bitri xxA|φxB|φxAφ¬xB¬φ
25 16 17 24 3bitr4ri xxA|φxB|φxxAB|φ
26 3 4 25 eqri xA|φxB|φ=xAB|φ