Metamath Proof Explorer


Theorem bj-imdirval2lem

Description: Lemma for bj-imdirval2 and bj-iminvval2 . (Contributed by BJ, 23-May-2024)

Ref Expression
Hypotheses bj-imdirval2lem.exa φAU
bj-imdirval2lem.exb φBV
Assertion bj-imdirval2lem φxy|xAyBψV

Proof

Step Hyp Ref Expression
1 bj-imdirval2lem.exa φAU
2 bj-imdirval2lem.exb φBV
3 1 pwexd φ𝒫AV
4 2 pwexd φ𝒫BV
5 simprl φxAyBxA
6 velpw x𝒫AxA
7 5 6 sylibr φxAyBx𝒫A
8 simprr φxAyByB
9 velpw y𝒫ByB
10 8 9 sylibr φxAyBy𝒫B
11 3 4 7 10 opabex2 φxy|xAyBV
12 simpl xAyBψxAyB
13 12 ssopab2i xy|xAyBψxy|xAyB
14 13 a1i φxy|xAyBψxy|xAyB
15 11 14 ssexd φxy|xAyBψV