Metamath Proof Explorer


Theorem orvcgteel

Description: Preimage maps produced by the "greater than or equal to" relation are measurable sets. (Contributed by Thierry Arnoux, 5-Feb-2017)

Ref Expression
Hypotheses orvcgteel.1 φ P Prob
orvcgteel.2 φ X RndVar P
orvcgteel.3 φ A
Assertion orvcgteel φ X -1 RV/c A dom P

Proof

Step Hyp Ref Expression
1 orvcgteel.1 φ P Prob
2 orvcgteel.2 φ X RndVar P
3 orvcgteel.3 φ A
4 simpr φ x x
5 3 adantr φ x A
6 brcnvg x A x -1 A A x
7 4 5 6 syl2anc φ x x -1 A A x
8 7 pm5.32da φ x x -1 A x A x
9 rexr x x *
10 9 ad2antrl φ x A x x *
11 simprr φ x A x A x
12 ltpnf x x < +∞
13 12 ad2antrl φ x A x x < +∞
14 11 13 jca φ x A x A x x < +∞
15 10 14 jca φ x A x x * A x x < +∞
16 simprl φ x * A x x < +∞ x *
17 3 adantr φ x * A x x < +∞ A
18 simprrl φ x * A x x < +∞ A x
19 simprrr φ x * A x x < +∞ x < +∞
20 xrre3 x * A A x x < +∞ x
21 16 17 18 19 20 syl22anc φ x * A x x < +∞ x
22 21 18 jca φ x * A x x < +∞ x A x
23 15 22 impbida φ x A x x * A x x < +∞
24 8 23 bitrd φ x x -1 A x * A x x < +∞
25 24 rabbidva2 φ x | x -1 A = x * | A x x < +∞
26 3 rexrd φ A *
27 pnfxr +∞ *
28 icoval A * +∞ * A +∞ = x * | A x x < +∞
29 26 27 28 sylancl φ A +∞ = x * | A x x < +∞
30 25 29 eqtr4d φ x | x -1 A = A +∞
31 icopnfcld A A +∞ Clsd topGen ran .
32 3 31 syl φ A +∞ Clsd topGen ran .
33 30 32 eqeltrd φ x | x -1 A Clsd topGen ran .
34 1 2 3 33 orrvccel φ X -1 RV/c A dom P