Metamath Proof Explorer


Theorem satefvfmla0

Description: The simplified satisfaction predicate for wff codes of height 0. (Contributed by AV, 4-Nov-2023)

Ref Expression
Assertion satefvfmla0 ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( 𝑀 Sat 𝑋 ) = { 𝑎 ∈ ( 𝑀m ω ) ∣ ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ∈ ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) } )

Proof

Step Hyp Ref Expression
1 satefv ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( 𝑀 Sat 𝑋 ) = ( ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ω ) ‘ 𝑋 ) )
2 incom ( E ∩ ( 𝑀 × 𝑀 ) ) = ( ( 𝑀 × 𝑀 ) ∩ E )
3 sqxpexg ( 𝑀𝑉 → ( 𝑀 × 𝑀 ) ∈ V )
4 inex1g ( ( 𝑀 × 𝑀 ) ∈ V → ( ( 𝑀 × 𝑀 ) ∩ E ) ∈ V )
5 3 4 syl ( 𝑀𝑉 → ( ( 𝑀 × 𝑀 ) ∩ E ) ∈ V )
6 2 5 eqeltrid ( 𝑀𝑉 → ( E ∩ ( 𝑀 × 𝑀 ) ) ∈ V )
7 6 ancli ( 𝑀𝑉 → ( 𝑀𝑉 ∧ ( E ∩ ( 𝑀 × 𝑀 ) ) ∈ V ) )
8 7 adantr ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( 𝑀𝑉 ∧ ( E ∩ ( 𝑀 × 𝑀 ) ) ∈ V ) )
9 satom ( ( 𝑀𝑉 ∧ ( E ∩ ( 𝑀 × 𝑀 ) ) ∈ V ) → ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ω ) = 𝑖 ∈ ω ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ 𝑖 ) )
10 8 9 syl ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ω ) = 𝑖 ∈ ω ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ 𝑖 ) )
11 10 fveq1d ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ω ) ‘ 𝑋 ) = ( 𝑖 ∈ ω ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ 𝑖 ) ‘ 𝑋 ) )
12 satfun ( ( 𝑀𝑉 ∧ ( E ∩ ( 𝑀 × 𝑀 ) ) ∈ V ) → ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ω ) : ( Fmla ‘ ω ) ⟶ 𝒫 ( 𝑀m ω ) )
13 8 12 syl ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ω ) : ( Fmla ‘ ω ) ⟶ 𝒫 ( 𝑀m ω ) )
14 13 ffund ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → Fun ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ω ) )
15 10 eqcomd ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → 𝑖 ∈ ω ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ 𝑖 ) = ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ω ) )
16 15 funeqd ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( Fun 𝑖 ∈ ω ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ 𝑖 ) ↔ Fun ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ω ) ) )
17 14 16 mpbird ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → Fun 𝑖 ∈ ω ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ 𝑖 ) )
18 peano1 ∅ ∈ ω
19 18 a1i ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ∅ ∈ ω )
20 18 a1i ( 𝑀𝑉 → ∅ ∈ ω )
21 satfdmfmla ( ( 𝑀𝑉 ∧ ( E ∩ ( 𝑀 × 𝑀 ) ) ∈ V ∧ ∅ ∈ ω ) → dom ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ∅ ) = ( Fmla ‘ ∅ ) )
22 6 20 21 mpd3an23 ( 𝑀𝑉 → dom ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ∅ ) = ( Fmla ‘ ∅ ) )
23 22 eqcomd ( 𝑀𝑉 → ( Fmla ‘ ∅ ) = dom ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ∅ ) )
24 23 eleq2d ( 𝑀𝑉 → ( 𝑋 ∈ ( Fmla ‘ ∅ ) ↔ 𝑋 ∈ dom ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ∅ ) ) )
25 24 biimpa ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → 𝑋 ∈ dom ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ∅ ) )
26 eqid 𝑖 ∈ ω ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ 𝑖 ) = 𝑖 ∈ ω ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ 𝑖 )
27 26 fviunfun ( ( Fun 𝑖 ∈ ω ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ 𝑖 ) ∧ ∅ ∈ ω ∧ 𝑋 ∈ dom ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ∅ ) ) → ( 𝑖 ∈ ω ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ 𝑖 ) ‘ 𝑋 ) = ( ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ∅ ) ‘ 𝑋 ) )
28 17 19 25 27 syl3anc ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( 𝑖 ∈ ω ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ 𝑖 ) ‘ 𝑋 ) = ( ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ∅ ) ‘ 𝑋 ) )
29 11 28 eqtrd ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ω ) ‘ 𝑋 ) = ( ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ∅ ) ‘ 𝑋 ) )
30 simpl ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → 𝑀𝑉 )
31 6 adantr ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( E ∩ ( 𝑀 × 𝑀 ) ) ∈ V )
32 simpr ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → 𝑋 ∈ ( Fmla ‘ ∅ ) )
33 eqid ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) = ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) )
34 33 satfv0fvfmla0 ( ( 𝑀𝑉 ∧ ( E ∩ ( 𝑀 × 𝑀 ) ) ∈ V ∧ 𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ∅ ) ‘ 𝑋 ) = { 𝑎 ∈ ( 𝑀m ω ) ∣ ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ( E ∩ ( 𝑀 × 𝑀 ) ) ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) } )
35 30 31 32 34 syl3anc ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ∅ ) ‘ 𝑋 ) = { 𝑎 ∈ ( 𝑀m ω ) ∣ ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ( E ∩ ( 𝑀 × 𝑀 ) ) ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) } )
36 elmapi ( 𝑎 ∈ ( 𝑀m ω ) → 𝑎 : ω ⟶ 𝑀 )
37 simpl ( ( 𝑎 : ω ⟶ 𝑀 ∧ ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) ) → 𝑎 : ω ⟶ 𝑀 )
38 fmla0xp ( Fmla ‘ ∅ ) = ( { ∅ } × ( ω × ω ) )
39 38 eleq2i ( 𝑋 ∈ ( Fmla ‘ ∅ ) ↔ 𝑋 ∈ ( { ∅ } × ( ω × ω ) ) )
40 elxp ( 𝑋 ∈ ( { ∅ } × ( ω × ω ) ) ↔ ∃ 𝑥𝑦 ( 𝑋 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ( 𝑥 ∈ { ∅ } ∧ 𝑦 ∈ ( ω × ω ) ) ) )
41 39 40 bitri ( 𝑋 ∈ ( Fmla ‘ ∅ ) ↔ ∃ 𝑥𝑦 ( 𝑋 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ( 𝑥 ∈ { ∅ } ∧ 𝑦 ∈ ( ω × ω ) ) ) )
42 xp1st ( 𝑦 ∈ ( ω × ω ) → ( 1st𝑦 ) ∈ ω )
43 42 ad2antll ( ( 𝑋 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ( 𝑥 ∈ { ∅ } ∧ 𝑦 ∈ ( ω × ω ) ) ) → ( 1st𝑦 ) ∈ ω )
44 vex 𝑥 ∈ V
45 vex 𝑦 ∈ V
46 44 45 op2ndd ( 𝑋 = ⟨ 𝑥 , 𝑦 ⟩ → ( 2nd𝑋 ) = 𝑦 )
47 46 fveq2d ( 𝑋 = ⟨ 𝑥 , 𝑦 ⟩ → ( 1st ‘ ( 2nd𝑋 ) ) = ( 1st𝑦 ) )
48 47 eleq1d ( 𝑋 = ⟨ 𝑥 , 𝑦 ⟩ → ( ( 1st ‘ ( 2nd𝑋 ) ) ∈ ω ↔ ( 1st𝑦 ) ∈ ω ) )
49 48 adantr ( ( 𝑋 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ( 𝑥 ∈ { ∅ } ∧ 𝑦 ∈ ( ω × ω ) ) ) → ( ( 1st ‘ ( 2nd𝑋 ) ) ∈ ω ↔ ( 1st𝑦 ) ∈ ω ) )
50 43 49 mpbird ( ( 𝑋 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ( 𝑥 ∈ { ∅ } ∧ 𝑦 ∈ ( ω × ω ) ) ) → ( 1st ‘ ( 2nd𝑋 ) ) ∈ ω )
51 50 exlimivv ( ∃ 𝑥𝑦 ( 𝑋 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ( 𝑥 ∈ { ∅ } ∧ 𝑦 ∈ ( ω × ω ) ) ) → ( 1st ‘ ( 2nd𝑋 ) ) ∈ ω )
52 41 51 sylbi ( 𝑋 ∈ ( Fmla ‘ ∅ ) → ( 1st ‘ ( 2nd𝑋 ) ) ∈ ω )
53 52 ad2antll ( ( 𝑎 : ω ⟶ 𝑀 ∧ ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) ) → ( 1st ‘ ( 2nd𝑋 ) ) ∈ ω )
54 37 53 ffvelrnd ( ( 𝑎 : ω ⟶ 𝑀 ∧ ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) ) → ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ∈ 𝑀 )
55 xp2nd ( 𝑦 ∈ ( ω × ω ) → ( 2nd𝑦 ) ∈ ω )
56 55 ad2antll ( ( 𝑋 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ( 𝑥 ∈ { ∅ } ∧ 𝑦 ∈ ( ω × ω ) ) ) → ( 2nd𝑦 ) ∈ ω )
57 46 fveq2d ( 𝑋 = ⟨ 𝑥 , 𝑦 ⟩ → ( 2nd ‘ ( 2nd𝑋 ) ) = ( 2nd𝑦 ) )
58 57 eleq1d ( 𝑋 = ⟨ 𝑥 , 𝑦 ⟩ → ( ( 2nd ‘ ( 2nd𝑋 ) ) ∈ ω ↔ ( 2nd𝑦 ) ∈ ω ) )
59 58 adantr ( ( 𝑋 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ( 𝑥 ∈ { ∅ } ∧ 𝑦 ∈ ( ω × ω ) ) ) → ( ( 2nd ‘ ( 2nd𝑋 ) ) ∈ ω ↔ ( 2nd𝑦 ) ∈ ω ) )
60 56 59 mpbird ( ( 𝑋 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ( 𝑥 ∈ { ∅ } ∧ 𝑦 ∈ ( ω × ω ) ) ) → ( 2nd ‘ ( 2nd𝑋 ) ) ∈ ω )
61 60 exlimivv ( ∃ 𝑥𝑦 ( 𝑋 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ( 𝑥 ∈ { ∅ } ∧ 𝑦 ∈ ( ω × ω ) ) ) → ( 2nd ‘ ( 2nd𝑋 ) ) ∈ ω )
62 41 61 sylbi ( 𝑋 ∈ ( Fmla ‘ ∅ ) → ( 2nd ‘ ( 2nd𝑋 ) ) ∈ ω )
63 62 ad2antll ( ( 𝑎 : ω ⟶ 𝑀 ∧ ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) ) → ( 2nd ‘ ( 2nd𝑋 ) ) ∈ ω )
64 37 63 ffvelrnd ( ( 𝑎 : ω ⟶ 𝑀 ∧ ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) ) → ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ∈ 𝑀 )
65 54 64 jca ( ( 𝑎 : ω ⟶ 𝑀 ∧ ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) ) → ( ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ∈ 𝑀 ∧ ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ∈ 𝑀 ) )
66 65 ex ( 𝑎 : ω ⟶ 𝑀 → ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ∈ 𝑀 ∧ ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ∈ 𝑀 ) ) )
67 36 66 syl ( 𝑎 ∈ ( 𝑀m ω ) → ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ∈ 𝑀 ∧ ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ∈ 𝑀 ) ) )
68 67 impcom ( ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) ∧ 𝑎 ∈ ( 𝑀m ω ) ) → ( ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ∈ 𝑀 ∧ ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ∈ 𝑀 ) )
69 brinxp ( ( ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ∈ 𝑀 ∧ ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ∈ 𝑀 ) → ( ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) E ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ↔ ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ( E ∩ ( 𝑀 × 𝑀 ) ) ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ) )
70 69 bicomd ( ( ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ∈ 𝑀 ∧ ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ∈ 𝑀 ) → ( ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ( E ∩ ( 𝑀 × 𝑀 ) ) ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ↔ ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) E ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ) )
71 68 70 syl ( ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) ∧ 𝑎 ∈ ( 𝑀m ω ) ) → ( ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ( E ∩ ( 𝑀 × 𝑀 ) ) ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ↔ ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) E ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ) )
72 fvex ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ∈ V
73 72 epeli ( ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) E ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ↔ ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ∈ ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) )
74 71 73 bitrdi ( ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) ∧ 𝑎 ∈ ( 𝑀m ω ) ) → ( ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ( E ∩ ( 𝑀 × 𝑀 ) ) ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ↔ ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ∈ ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) ) )
75 74 rabbidva ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → { 𝑎 ∈ ( 𝑀m ω ) ∣ ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ( E ∩ ( 𝑀 × 𝑀 ) ) ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) } = { 𝑎 ∈ ( 𝑀m ω ) ∣ ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ∈ ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) } )
76 35 75 eqtrd ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ∅ ) ‘ 𝑋 ) = { 𝑎 ∈ ( 𝑀m ω ) ∣ ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ∈ ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) } )
77 29 76 eqtrd ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( ( ( 𝑀 Sat ( E ∩ ( 𝑀 × 𝑀 ) ) ) ‘ ω ) ‘ 𝑋 ) = { 𝑎 ∈ ( 𝑀m ω ) ∣ ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ∈ ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) } )
78 1 77 eqtrd ( ( 𝑀𝑉𝑋 ∈ ( Fmla ‘ ∅ ) ) → ( 𝑀 Sat 𝑋 ) = { 𝑎 ∈ ( 𝑀m ω ) ∣ ( 𝑎 ‘ ( 1st ‘ ( 2nd𝑋 ) ) ) ∈ ( 𝑎 ‘ ( 2nd ‘ ( 2nd𝑋 ) ) ) } )