| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dstrvprob.1 | ⊢ ( 𝜑  →  𝑃  ∈  Prob ) | 
						
							| 2 |  | dstrvprob.2 | ⊢ ( 𝜑  →  𝑋  ∈  ( rRndVar ‘ 𝑃 ) ) | 
						
							| 3 |  | dstrvprob.3 | ⊢ ( 𝜑  →  𝐷  =  ( 𝑎  ∈  𝔅ℝ  ↦  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) ) ) ) | 
						
							| 4 | 1 | adantr | ⊢ ( ( 𝜑  ∧  𝑎  ∈  𝔅ℝ )  →  𝑃  ∈  Prob ) | 
						
							| 5 | 2 | adantr | ⊢ ( ( 𝜑  ∧  𝑎  ∈  𝔅ℝ )  →  𝑋  ∈  ( rRndVar ‘ 𝑃 ) ) | 
						
							| 6 |  | simpr | ⊢ ( ( 𝜑  ∧  𝑎  ∈  𝔅ℝ )  →  𝑎  ∈  𝔅ℝ ) | 
						
							| 7 | 4 5 6 | orvcelel | ⊢ ( ( 𝜑  ∧  𝑎  ∈  𝔅ℝ )  →  ( 𝑋 ∘RV/𝑐  E  𝑎 )  ∈  dom  𝑃 ) | 
						
							| 8 |  | prob01 | ⊢ ( ( 𝑃  ∈  Prob  ∧  ( 𝑋 ∘RV/𝑐  E  𝑎 )  ∈  dom  𝑃 )  →  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  ∈  ( 0 [,] 1 ) ) | 
						
							| 9 | 4 7 8 | syl2anc | ⊢ ( ( 𝜑  ∧  𝑎  ∈  𝔅ℝ )  →  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  ∈  ( 0 [,] 1 ) ) | 
						
							| 10 |  | elunitrn | ⊢ ( ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  ∈  ( 0 [,] 1 )  →  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  ∈  ℝ ) | 
						
							| 11 | 10 | rexrd | ⊢ ( ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  ∈  ( 0 [,] 1 )  →  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  ∈  ℝ* ) | 
						
							| 12 |  | elunitge0 | ⊢ ( ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  ∈  ( 0 [,] 1 )  →  0  ≤  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) ) ) | 
						
							| 13 |  | elxrge0 | ⊢ ( ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  ∈  ( 0 [,] +∞ )  ↔  ( ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  ∈  ℝ*  ∧  0  ≤  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) ) ) ) | 
						
							| 14 | 11 12 13 | sylanbrc | ⊢ ( ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  ∈  ( 0 [,] 1 )  →  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  ∈  ( 0 [,] +∞ ) ) | 
						
							| 15 | 9 14 | syl | ⊢ ( ( 𝜑  ∧  𝑎  ∈  𝔅ℝ )  →  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  ∈  ( 0 [,] +∞ ) ) | 
						
							| 16 | 3 15 | fmpt3d | ⊢ ( 𝜑  →  𝐷 : 𝔅ℝ ⟶ ( 0 [,] +∞ ) ) | 
						
							| 17 |  | simpr | ⊢ ( ( 𝜑  ∧  𝑎  =  ∅ )  →  𝑎  =  ∅ ) | 
						
							| 18 | 17 | oveq2d | ⊢ ( ( 𝜑  ∧  𝑎  =  ∅ )  →  ( 𝑋 ∘RV/𝑐  E  𝑎 )  =  ( 𝑋 ∘RV/𝑐  E  ∅ ) ) | 
						
							| 19 | 18 | fveq2d | ⊢ ( ( 𝜑  ∧  𝑎  =  ∅ )  →  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  =  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  ∅ ) ) ) | 
						
							| 20 |  | brsigarn | ⊢ 𝔅ℝ  ∈  ( sigAlgebra ‘ ℝ ) | 
						
							| 21 |  | elrnsiga | ⊢ ( 𝔅ℝ  ∈  ( sigAlgebra ‘ ℝ )  →  𝔅ℝ  ∈  ∪  ran  sigAlgebra ) | 
						
							| 22 |  | 0elsiga | ⊢ ( 𝔅ℝ  ∈  ∪  ran  sigAlgebra  →  ∅  ∈  𝔅ℝ ) | 
						
							| 23 | 20 21 22 | mp2b | ⊢ ∅  ∈  𝔅ℝ | 
						
							| 24 | 23 | a1i | ⊢ ( 𝜑  →  ∅  ∈  𝔅ℝ ) | 
						
							| 25 | 1 2 24 | orvcelel | ⊢ ( 𝜑  →  ( 𝑋 ∘RV/𝑐  E  ∅ )  ∈  dom  𝑃 ) | 
						
							| 26 | 1 25 | probvalrnd | ⊢ ( 𝜑  →  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  ∅ ) )  ∈  ℝ ) | 
						
							| 27 | 3 19 24 26 | fvmptd | ⊢ ( 𝜑  →  ( 𝐷 ‘ ∅ )  =  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  ∅ ) ) ) | 
						
							| 28 | 1 2 24 | orvcelval | ⊢ ( 𝜑  →  ( 𝑋 ∘RV/𝑐  E  ∅ )  =  ( ◡ 𝑋  “  ∅ ) ) | 
						
							| 29 | 28 | fveq2d | ⊢ ( 𝜑  →  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  ∅ ) )  =  ( 𝑃 ‘ ( ◡ 𝑋  “  ∅ ) ) ) | 
						
							| 30 |  | ima0 | ⊢ ( ◡ 𝑋  “  ∅ )  =  ∅ | 
						
							| 31 | 30 | fveq2i | ⊢ ( 𝑃 ‘ ( ◡ 𝑋  “  ∅ ) )  =  ( 𝑃 ‘ ∅ ) | 
						
							| 32 |  | probnul | ⊢ ( 𝑃  ∈  Prob  →  ( 𝑃 ‘ ∅ )  =  0 ) | 
						
							| 33 | 1 32 | syl | ⊢ ( 𝜑  →  ( 𝑃 ‘ ∅ )  =  0 ) | 
						
							| 34 | 31 33 | eqtrid | ⊢ ( 𝜑  →  ( 𝑃 ‘ ( ◡ 𝑋  “  ∅ ) )  =  0 ) | 
						
							| 35 | 27 29 34 | 3eqtrd | ⊢ ( 𝜑  →  ( 𝐷 ‘ ∅ )  =  0 ) | 
						
							| 36 | 1 2 | rrvvf | ⊢ ( 𝜑  →  𝑋 : ∪  dom  𝑃 ⟶ ℝ ) | 
						
							| 37 | 36 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  𝑋 : ∪  dom  𝑃 ⟶ ℝ ) | 
						
							| 38 | 37 | ffund | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  Fun  𝑋 ) | 
						
							| 39 |  | unipreima | ⊢ ( Fun  𝑋  →  ( ◡ 𝑋  “  ∪  𝑥 )  =  ∪  𝑎  ∈  𝑥 ( ◡ 𝑋  “  𝑎 ) ) | 
						
							| 40 | 39 | fveq2d | ⊢ ( Fun  𝑋  →  ( 𝑃 ‘ ( ◡ 𝑋  “  ∪  𝑥 ) )  =  ( 𝑃 ‘ ∪  𝑎  ∈  𝑥 ( ◡ 𝑋  “  𝑎 ) ) ) | 
						
							| 41 | 38 40 | syl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  ( 𝑃 ‘ ( ◡ 𝑋  “  ∪  𝑥 ) )  =  ( 𝑃 ‘ ∪  𝑎  ∈  𝑥 ( ◡ 𝑋  “  𝑎 ) ) ) | 
						
							| 42 | 1 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  𝑃  ∈  Prob ) | 
						
							| 43 |  | domprobmeas | ⊢ ( 𝑃  ∈  Prob  →  𝑃  ∈  ( measures ‘ dom  𝑃 ) ) | 
						
							| 44 | 42 43 | syl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  𝑃  ∈  ( measures ‘ dom  𝑃 ) ) | 
						
							| 45 |  | nfv | ⊢ Ⅎ 𝑎 ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ ) | 
						
							| 46 |  | nfv | ⊢ Ⅎ 𝑎 𝑥  ≼  ω | 
						
							| 47 |  | nfdisj1 | ⊢ Ⅎ 𝑎 Disj  𝑎  ∈  𝑥 𝑎 | 
						
							| 48 | 46 47 | nfan | ⊢ Ⅎ 𝑎 ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) | 
						
							| 49 | 45 48 | nfan | ⊢ Ⅎ 𝑎 ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) ) | 
						
							| 50 |  | simplll | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  ∧  𝑎  ∈  𝑥 )  →  𝜑 ) | 
						
							| 51 |  | simpr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  ∧  𝑎  ∈  𝑥 )  →  𝑎  ∈  𝑥 ) | 
						
							| 52 |  | simpllr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  ∧  𝑎  ∈  𝑥 )  →  𝑥  ∈  𝒫  𝔅ℝ ) | 
						
							| 53 |  | elelpwi | ⊢ ( ( 𝑎  ∈  𝑥  ∧  𝑥  ∈  𝒫  𝔅ℝ )  →  𝑎  ∈  𝔅ℝ ) | 
						
							| 54 | 51 52 53 | syl2anc | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  ∧  𝑎  ∈  𝑥 )  →  𝑎  ∈  𝔅ℝ ) | 
						
							| 55 | 1 2 | rrvfinvima | ⊢ ( 𝜑  →  ∀ 𝑎  ∈  𝔅ℝ ( ◡ 𝑋  “  𝑎 )  ∈  dom  𝑃 ) | 
						
							| 56 | 55 | r19.21bi | ⊢ ( ( 𝜑  ∧  𝑎  ∈  𝔅ℝ )  →  ( ◡ 𝑋  “  𝑎 )  ∈  dom  𝑃 ) | 
						
							| 57 | 50 54 56 | syl2anc | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  ∧  𝑎  ∈  𝑥 )  →  ( ◡ 𝑋  “  𝑎 )  ∈  dom  𝑃 ) | 
						
							| 58 | 57 | ex | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  ( 𝑎  ∈  𝑥  →  ( ◡ 𝑋  “  𝑎 )  ∈  dom  𝑃 ) ) | 
						
							| 59 | 49 58 | ralrimi | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  ∀ 𝑎  ∈  𝑥 ( ◡ 𝑋  “  𝑎 )  ∈  dom  𝑃 ) | 
						
							| 60 |  | simprl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  𝑥  ≼  ω ) | 
						
							| 61 |  | simprr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  Disj  𝑎  ∈  𝑥 𝑎 ) | 
						
							| 62 |  | disjpreima | ⊢ ( ( Fun  𝑋  ∧  Disj  𝑎  ∈  𝑥 𝑎 )  →  Disj  𝑎  ∈  𝑥 ( ◡ 𝑋  “  𝑎 ) ) | 
						
							| 63 | 38 61 62 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  Disj  𝑎  ∈  𝑥 ( ◡ 𝑋  “  𝑎 ) ) | 
						
							| 64 |  | measvuni | ⊢ ( ( 𝑃  ∈  ( measures ‘ dom  𝑃 )  ∧  ∀ 𝑎  ∈  𝑥 ( ◡ 𝑋  “  𝑎 )  ∈  dom  𝑃  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 ( ◡ 𝑋  “  𝑎 ) ) )  →  ( 𝑃 ‘ ∪  𝑎  ∈  𝑥 ( ◡ 𝑋  “  𝑎 ) )  =  Σ* 𝑎  ∈  𝑥 ( 𝑃 ‘ ( ◡ 𝑋  “  𝑎 ) ) ) | 
						
							| 65 | 44 59 60 63 64 | syl112anc | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  ( 𝑃 ‘ ∪  𝑎  ∈  𝑥 ( ◡ 𝑋  “  𝑎 ) )  =  Σ* 𝑎  ∈  𝑥 ( 𝑃 ‘ ( ◡ 𝑋  “  𝑎 ) ) ) | 
						
							| 66 | 41 65 | eqtrd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  ( 𝑃 ‘ ( ◡ 𝑋  “  ∪  𝑥 ) )  =  Σ* 𝑎  ∈  𝑥 ( 𝑃 ‘ ( ◡ 𝑋  “  𝑎 ) ) ) | 
						
							| 67 | 2 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  𝑋  ∈  ( rRndVar ‘ 𝑃 ) ) | 
						
							| 68 | 3 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  𝐷  =  ( 𝑎  ∈  𝔅ℝ  ↦  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) ) ) ) | 
						
							| 69 | 20 21 | mp1i | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  𝔅ℝ  ∈  ∪  ran  sigAlgebra ) | 
						
							| 70 |  | simplr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  𝑥  ∈  𝒫  𝔅ℝ ) | 
						
							| 71 |  | sigaclcu | ⊢ ( ( 𝔅ℝ  ∈  ∪  ran  sigAlgebra  ∧  𝑥  ∈  𝒫  𝔅ℝ  ∧  𝑥  ≼  ω )  →  ∪  𝑥  ∈  𝔅ℝ ) | 
						
							| 72 | 69 70 60 71 | syl3anc | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  ∪  𝑥  ∈  𝔅ℝ ) | 
						
							| 73 | 42 67 68 72 | dstrvval | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  ( 𝐷 ‘ ∪  𝑥 )  =  ( 𝑃 ‘ ( ◡ 𝑋  “  ∪  𝑥 ) ) ) | 
						
							| 74 | 3 9 | fvmpt2d | ⊢ ( ( 𝜑  ∧  𝑎  ∈  𝔅ℝ )  →  ( 𝐷 ‘ 𝑎 )  =  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) ) ) | 
						
							| 75 | 50 54 74 | syl2anc | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  ∧  𝑎  ∈  𝑥 )  →  ( 𝐷 ‘ 𝑎 )  =  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) ) ) | 
						
							| 76 | 42 | adantr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  ∧  𝑎  ∈  𝑥 )  →  𝑃  ∈  Prob ) | 
						
							| 77 | 67 | adantr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  ∧  𝑎  ∈  𝑥 )  →  𝑋  ∈  ( rRndVar ‘ 𝑃 ) ) | 
						
							| 78 | 76 77 54 | orvcelval | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  ∧  𝑎  ∈  𝑥 )  →  ( 𝑋 ∘RV/𝑐  E  𝑎 )  =  ( ◡ 𝑋  “  𝑎 ) ) | 
						
							| 79 | 78 | fveq2d | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  ∧  𝑎  ∈  𝑥 )  →  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  =  ( 𝑃 ‘ ( ◡ 𝑋  “  𝑎 ) ) ) | 
						
							| 80 | 75 79 | eqtrd | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  ∧  𝑎  ∈  𝑥 )  →  ( 𝐷 ‘ 𝑎 )  =  ( 𝑃 ‘ ( ◡ 𝑋  “  𝑎 ) ) ) | 
						
							| 81 | 80 | ex | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  ( 𝑎  ∈  𝑥  →  ( 𝐷 ‘ 𝑎 )  =  ( 𝑃 ‘ ( ◡ 𝑋  “  𝑎 ) ) ) ) | 
						
							| 82 | 49 81 | ralrimi | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  ∀ 𝑎  ∈  𝑥 ( 𝐷 ‘ 𝑎 )  =  ( 𝑃 ‘ ( ◡ 𝑋  “  𝑎 ) ) ) | 
						
							| 83 | 49 82 | esumeq2d | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  Σ* 𝑎  ∈  𝑥 ( 𝐷 ‘ 𝑎 )  =  Σ* 𝑎  ∈  𝑥 ( 𝑃 ‘ ( ◡ 𝑋  “  𝑎 ) ) ) | 
						
							| 84 | 66 73 83 | 3eqtr4d | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 ) )  →  ( 𝐷 ‘ ∪  𝑥 )  =  Σ* 𝑎  ∈  𝑥 ( 𝐷 ‘ 𝑎 ) ) | 
						
							| 85 | 84 | ex | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝒫  𝔅ℝ )  →  ( ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 )  →  ( 𝐷 ‘ ∪  𝑥 )  =  Σ* 𝑎  ∈  𝑥 ( 𝐷 ‘ 𝑎 ) ) ) | 
						
							| 86 | 85 | ralrimiva | ⊢ ( 𝜑  →  ∀ 𝑥  ∈  𝒫  𝔅ℝ ( ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 )  →  ( 𝐷 ‘ ∪  𝑥 )  =  Σ* 𝑎  ∈  𝑥 ( 𝐷 ‘ 𝑎 ) ) ) | 
						
							| 87 |  | ismeas | ⊢ ( 𝔅ℝ  ∈  ∪  ran  sigAlgebra  →  ( 𝐷  ∈  ( measures ‘ 𝔅ℝ )  ↔  ( 𝐷 : 𝔅ℝ ⟶ ( 0 [,] +∞ )  ∧  ( 𝐷 ‘ ∅ )  =  0  ∧  ∀ 𝑥  ∈  𝒫  𝔅ℝ ( ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 )  →  ( 𝐷 ‘ ∪  𝑥 )  =  Σ* 𝑎  ∈  𝑥 ( 𝐷 ‘ 𝑎 ) ) ) ) ) | 
						
							| 88 | 20 21 87 | mp2b | ⊢ ( 𝐷  ∈  ( measures ‘ 𝔅ℝ )  ↔  ( 𝐷 : 𝔅ℝ ⟶ ( 0 [,] +∞ )  ∧  ( 𝐷 ‘ ∅ )  =  0  ∧  ∀ 𝑥  ∈  𝒫  𝔅ℝ ( ( 𝑥  ≼  ω  ∧  Disj  𝑎  ∈  𝑥 𝑎 )  →  ( 𝐷 ‘ ∪  𝑥 )  =  Σ* 𝑎  ∈  𝑥 ( 𝐷 ‘ 𝑎 ) ) ) ) | 
						
							| 89 | 16 35 86 88 | syl3anbrc | ⊢ ( 𝜑  →  𝐷  ∈  ( measures ‘ 𝔅ℝ ) ) | 
						
							| 90 | 3 | dmeqd | ⊢ ( 𝜑  →  dom  𝐷  =  dom  ( 𝑎  ∈  𝔅ℝ  ↦  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) ) ) ) | 
						
							| 91 | 15 | ralrimiva | ⊢ ( 𝜑  →  ∀ 𝑎  ∈  𝔅ℝ ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  ∈  ( 0 [,] +∞ ) ) | 
						
							| 92 |  | dmmptg | ⊢ ( ∀ 𝑎  ∈  𝔅ℝ ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  ∈  ( 0 [,] +∞ )  →  dom  ( 𝑎  ∈  𝔅ℝ  ↦  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) ) )  =  𝔅ℝ ) | 
						
							| 93 | 91 92 | syl | ⊢ ( 𝜑  →  dom  ( 𝑎  ∈  𝔅ℝ  ↦  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) ) )  =  𝔅ℝ ) | 
						
							| 94 | 90 93 | eqtrd | ⊢ ( 𝜑  →  dom  𝐷  =  𝔅ℝ ) | 
						
							| 95 | 94 | fveq2d | ⊢ ( 𝜑  →  ( measures ‘ dom  𝐷 )  =  ( measures ‘ 𝔅ℝ ) ) | 
						
							| 96 | 89 95 | eleqtrrd | ⊢ ( 𝜑  →  𝐷  ∈  ( measures ‘ dom  𝐷 ) ) | 
						
							| 97 |  | measbasedom | ⊢ ( 𝐷  ∈  ∪  ran  measures  ↔  𝐷  ∈  ( measures ‘ dom  𝐷 ) ) | 
						
							| 98 | 96 97 | sylibr | ⊢ ( 𝜑  →  𝐷  ∈  ∪  ran  measures ) | 
						
							| 99 | 94 | unieqd | ⊢ ( 𝜑  →  ∪  dom  𝐷  =  ∪  𝔅ℝ ) | 
						
							| 100 |  | unibrsiga | ⊢ ∪  𝔅ℝ  =  ℝ | 
						
							| 101 | 99 100 | eqtrdi | ⊢ ( 𝜑  →  ∪  dom  𝐷  =  ℝ ) | 
						
							| 102 | 101 | fveq2d | ⊢ ( 𝜑  →  ( 𝐷 ‘ ∪  dom  𝐷 )  =  ( 𝐷 ‘ ℝ ) ) | 
						
							| 103 |  | simpr | ⊢ ( ( 𝜑  ∧  𝑎  =  ℝ )  →  𝑎  =  ℝ ) | 
						
							| 104 | 103 | oveq2d | ⊢ ( ( 𝜑  ∧  𝑎  =  ℝ )  →  ( 𝑋 ∘RV/𝑐  E  𝑎 )  =  ( 𝑋 ∘RV/𝑐  E  ℝ ) ) | 
						
							| 105 |  | baselsiga | ⊢ ( 𝔅ℝ  ∈  ( sigAlgebra ‘ ℝ )  →  ℝ  ∈  𝔅ℝ ) | 
						
							| 106 | 20 105 | mp1i | ⊢ ( 𝜑  →  ℝ  ∈  𝔅ℝ ) | 
						
							| 107 | 1 2 106 | orvcelval | ⊢ ( 𝜑  →  ( 𝑋 ∘RV/𝑐  E  ℝ )  =  ( ◡ 𝑋  “  ℝ ) ) | 
						
							| 108 | 107 | adantr | ⊢ ( ( 𝜑  ∧  𝑎  =  ℝ )  →  ( 𝑋 ∘RV/𝑐  E  ℝ )  =  ( ◡ 𝑋  “  ℝ ) ) | 
						
							| 109 | 104 108 | eqtrd | ⊢ ( ( 𝜑  ∧  𝑎  =  ℝ )  →  ( 𝑋 ∘RV/𝑐  E  𝑎 )  =  ( ◡ 𝑋  “  ℝ ) ) | 
						
							| 110 | 109 | fveq2d | ⊢ ( ( 𝜑  ∧  𝑎  =  ℝ )  →  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  =  ( 𝑃 ‘ ( ◡ 𝑋  “  ℝ ) ) ) | 
						
							| 111 |  | fimacnv | ⊢ ( 𝑋 : ∪  dom  𝑃 ⟶ ℝ  →  ( ◡ 𝑋  “  ℝ )  =  ∪  dom  𝑃 ) | 
						
							| 112 | 36 111 | syl | ⊢ ( 𝜑  →  ( ◡ 𝑋  “  ℝ )  =  ∪  dom  𝑃 ) | 
						
							| 113 | 112 | fveq2d | ⊢ ( 𝜑  →  ( 𝑃 ‘ ( ◡ 𝑋  “  ℝ ) )  =  ( 𝑃 ‘ ∪  dom  𝑃 ) ) | 
						
							| 114 |  | probtot | ⊢ ( 𝑃  ∈  Prob  →  ( 𝑃 ‘ ∪  dom  𝑃 )  =  1 ) | 
						
							| 115 | 1 114 | syl | ⊢ ( 𝜑  →  ( 𝑃 ‘ ∪  dom  𝑃 )  =  1 ) | 
						
							| 116 | 113 115 | eqtrd | ⊢ ( 𝜑  →  ( 𝑃 ‘ ( ◡ 𝑋  “  ℝ ) )  =  1 ) | 
						
							| 117 | 116 | adantr | ⊢ ( ( 𝜑  ∧  𝑎  =  ℝ )  →  ( 𝑃 ‘ ( ◡ 𝑋  “  ℝ ) )  =  1 ) | 
						
							| 118 | 110 117 | eqtrd | ⊢ ( ( 𝜑  ∧  𝑎  =  ℝ )  →  ( 𝑃 ‘ ( 𝑋 ∘RV/𝑐  E  𝑎 ) )  =  1 ) | 
						
							| 119 |  | 1red | ⊢ ( 𝜑  →  1  ∈  ℝ ) | 
						
							| 120 | 3 118 106 119 | fvmptd | ⊢ ( 𝜑  →  ( 𝐷 ‘ ℝ )  =  1 ) | 
						
							| 121 | 102 120 | eqtrd | ⊢ ( 𝜑  →  ( 𝐷 ‘ ∪  dom  𝐷 )  =  1 ) | 
						
							| 122 |  | elprob | ⊢ ( 𝐷  ∈  Prob  ↔  ( 𝐷  ∈  ∪  ran  measures  ∧  ( 𝐷 ‘ ∪  dom  𝐷 )  =  1 ) ) | 
						
							| 123 | 98 121 122 | sylanbrc | ⊢ ( 𝜑  →  𝐷  ∈  Prob ) |