Metamath Proof Explorer


Theorem sssmf

Description: The restriction of a sigma-measurable function, is sigma-measurable. (Contributed by Glauco Siliprandi, 26-Jun-2021)

Ref Expression
Hypotheses sssmf.s φ S SAlg
sssmf.f φ F SMblFn S
Assertion sssmf φ F B SMblFn S

Proof

Step Hyp Ref Expression
1 sssmf.s φ S SAlg
2 sssmf.f φ F SMblFn S
3 nfv a φ
4 inss2 B dom F dom F
5 eqid dom F = dom F
6 1 2 5 smfdmss φ dom F S
7 4 6 sstrid φ B dom F S
8 1 2 5 smff φ F : dom F
9 4 a1i φ B dom F dom F
10 fssres F : dom F B dom F dom F F B dom F : B dom F
11 8 9 10 syl2anc φ F B dom F : B dom F
12 8 freld φ Rel F
13 resindm Rel F F B dom F = F B
14 12 13 syl φ F B dom F = F B
15 14 eqcomd φ F B = F B dom F
16 dmres dom F B = B dom F
17 16 a1i φ dom F B = B dom F
18 15 17 feq12d φ F B : dom F B F B dom F : B dom F
19 11 18 mpbird φ F B : dom F B
20 17 feq2d φ F B : dom F B F B : B dom F
21 19 20 mpbid φ F B : B dom F
22 1 adantr φ a S SAlg
23 2 adantr φ a F SMblFn S
24 simpr φ a a
25 22 23 5 24 smfpreimalt φ a x dom F | F x < a S 𝑡 dom F
26 2 dmexd φ dom F V
27 elrest S SAlg dom F V x dom F | F x < a S 𝑡 dom F w S x dom F | F x < a = w dom F
28 1 26 27 syl2anc φ x dom F | F x < a S 𝑡 dom F w S x dom F | F x < a = w dom F
29 28 adantr φ a x dom F | F x < a S 𝑡 dom F w S x dom F | F x < a = w dom F
30 25 29 mpbid φ a w S x dom F | F x < a = w dom F
31 elinel1 x B dom F x B
32 31 fvresd x B dom F F B x = F x
33 32 breq1d x B dom F F B x < a F x < a
34 33 rabbiia x B dom F | F B x < a = x B dom F | F x < a
35 34 a1i x dom F | F x < a = w dom F x B dom F | F B x < a = x B dom F | F x < a
36 rabss2 B dom F dom F x B dom F | F x < a x dom F | F x < a
37 4 36 ax-mp x B dom F | F x < a x dom F | F x < a
38 id x dom F | F x < a = w dom F x dom F | F x < a = w dom F
39 inss1 w dom F w
40 39 a1i x dom F | F x < a = w dom F w dom F w
41 38 40 eqsstrd x dom F | F x < a = w dom F x dom F | F x < a w
42 37 41 sstrid x dom F | F x < a = w dom F x B dom F | F x < a w
43 ssrab2 x B dom F | F x < a B dom F
44 43 a1i x dom F | F x < a = w dom F x B dom F | F x < a B dom F
45 42 44 ssind x dom F | F x < a = w dom F x B dom F | F x < a w B dom F
46 nfrab1 _ x x dom F | F x < a
47 nfcv _ x w dom F
48 46 47 nfeq x x dom F | F x < a = w dom F
49 elinel2 x w B dom F x B dom F
50 49 adantl x dom F | F x < a = w dom F x w B dom F x B dom F
51 elinel1 x w B dom F x w
52 4 sseli x B dom F x dom F
53 49 52 syl x w B dom F x dom F
54 51 53 elind x w B dom F x w dom F
55 54 adantl x dom F | F x < a = w dom F x w B dom F x w dom F
56 38 eqcomd x dom F | F x < a = w dom F w dom F = x dom F | F x < a
57 56 adantr x dom F | F x < a = w dom F x w B dom F w dom F = x dom F | F x < a
58 55 57 eleqtrd x dom F | F x < a = w dom F x w B dom F x x dom F | F x < a
59 rabid x x dom F | F x < a x dom F F x < a
60 59 biimpi x x dom F | F x < a x dom F F x < a
61 60 simprd x x dom F | F x < a F x < a
62 58 61 syl x dom F | F x < a = w dom F x w B dom F F x < a
63 50 62 jca x dom F | F x < a = w dom F x w B dom F x B dom F F x < a
64 rabid x x B dom F | F x < a x B dom F F x < a
65 63 64 sylibr x dom F | F x < a = w dom F x w B dom F x x B dom F | F x < a
66 65 ex x dom F | F x < a = w dom F x w B dom F x x B dom F | F x < a
67 48 66 ralrimi x dom F | F x < a = w dom F x w B dom F x x B dom F | F x < a
68 nfcv _ x w B dom F
69 nfrab1 _ x x B dom F | F x < a
70 68 69 dfss3f w B dom F x B dom F | F x < a x w B dom F x x B dom F | F x < a
71 67 70 sylibr x dom F | F x < a = w dom F w B dom F x B dom F | F x < a
72 71 sseld x dom F | F x < a = w dom F x w B dom F x x B dom F | F x < a
73 48 72 ralrimi x dom F | F x < a = w dom F x w B dom F x x B dom F | F x < a
74 73 70 sylibr x dom F | F x < a = w dom F w B dom F x B dom F | F x < a
75 45 74 eqssd x dom F | F x < a = w dom F x B dom F | F x < a = w B dom F
76 35 75 eqtrd x dom F | F x < a = w dom F x B dom F | F B x < a = w B dom F
77 76 adantl φ a x dom F | F x < a = w dom F x B dom F | F B x < a = w B dom F
78 77 3adant2 φ a w S x dom F | F x < a = w dom F x B dom F | F B x < a = w B dom F
79 22 3ad2ant1 φ a w S x dom F | F x < a = w dom F S SAlg
80 simp1l φ a w S x dom F | F x < a = w dom F φ
81 26 9 ssexd φ B dom F V
82 80 81 syl φ a w S x dom F | F x < a = w dom F B dom F V
83 simp2 φ a w S x dom F | F x < a = w dom F w S
84 eqid w B dom F = w B dom F
85 79 82 83 84 elrestd φ a w S x dom F | F x < a = w dom F w B dom F S 𝑡 B dom F
86 78 85 eqeltrd φ a w S x dom F | F x < a = w dom F x B dom F | F B x < a S 𝑡 B dom F
87 86 3exp φ a w S x dom F | F x < a = w dom F x B dom F | F B x < a S 𝑡 B dom F
88 87 rexlimdv φ a w S x dom F | F x < a = w dom F x B dom F | F B x < a S 𝑡 B dom F
89 30 88 mpd φ a x B dom F | F B x < a S 𝑡 B dom F
90 3 1 7 21 89 issmfd φ F B SMblFn S