| Step | Hyp | Ref
 | Expression | 
| 1 |   | ncaddccl 6145 | 
. . . 4
⊢ ((M ∈ NC ∧ N ∈ NC ) → (M
+c N) ∈ NC
) | 
| 2 |   | ce0nnul 6178 | 
. . . . 5
⊢ ((M +c N) ∈ NC → (((M
+c N)
↑c 0c) ≠ ∅ ↔ ∃a℘1a ∈ (M +c N))) | 
| 3 |   | eladdc 4399 | 
. . . . . 6
⊢ (℘1a ∈ (M +c N) ↔ ∃b ∈ M ∃g ∈ N ((b ∩ g) =
∅ ∧ ℘1a = (b ∪
g))) | 
| 4 | 3 | exbii 1582 | 
. . . . 5
⊢ (∃a℘1a ∈ (M +c N) ↔ ∃a∃b ∈ M ∃g ∈ N ((b ∩ g) =
∅ ∧ ℘1a = (b ∪
g))) | 
| 5 | 2, 4 | syl6bb 252 | 
. . . 4
⊢ ((M +c N) ∈ NC → (((M
+c N)
↑c 0c) ≠ ∅ ↔ ∃a∃b ∈ M ∃g ∈ N ((b ∩ g) =
∅ ∧ ℘1a = (b ∪
g)))) | 
| 6 | 1, 5 | syl 15 | 
. . 3
⊢ ((M ∈ NC ∧ N ∈ NC ) → (((M
+c N)
↑c 0c) ≠ ∅ ↔ ∃a∃b ∈ M ∃g ∈ N ((b ∩ g) =
∅ ∧ ℘1a = (b ∪
g)))) | 
| 7 |   | ncseqnc 6129 | 
. . . . . . . 8
⊢ (M ∈ NC → (M = Nc b ↔ b ∈ M)) | 
| 8 |   | ncseqnc 6129 | 
. . . . . . . 8
⊢ (N ∈ NC → (N = Nc g ↔ g ∈ N)) | 
| 9 | 7, 8 | bi2anan9 843 | 
. . . . . . 7
⊢ ((M ∈ NC ∧ N ∈ NC ) → ((M =
Nc b ∧ N = Nc g) ↔
(b ∈
M ∧
g ∈
N))) | 
| 10 | 9 | biimpar 471 | 
. . . . . 6
⊢ (((M ∈ NC ∧ N ∈ NC ) ∧ (b ∈ M ∧ g ∈ N)) → (M =
Nc b ∧ N = Nc g)) | 
| 11 |   | ssun1 3427 | 
. . . . . . . . . . . 12
⊢ b ⊆ (b ∪ g) | 
| 12 |   | id 19 | 
. . . . . . . . . . . 12
⊢ (℘1a = (b ∪
g) → ℘1a = (b ∪
g)) | 
| 13 | 11, 12 | syl5sseqr 3321 | 
. . . . . . . . . . 11
⊢ (℘1a = (b ∪
g) → b ⊆ ℘1a) | 
| 14 |   | ssun2 3428 | 
. . . . . . . . . . . 12
⊢ g ⊆ (b ∪ g) | 
| 15 | 14, 12 | syl5sseqr 3321 | 
. . . . . . . . . . 11
⊢ (℘1a = (b ∪
g) → g ⊆ ℘1a) | 
| 16 | 13, 15 | jca 518 | 
. . . . . . . . . 10
⊢ (℘1a = (b ∪
g) → (b ⊆ ℘1a ∧ g ⊆ ℘1a)) | 
| 17 |   | vex 2863 | 
. . . . . . . . . . . . 13
⊢ b ∈
V | 
| 18 | 17 | sspw1 4336 | 
. . . . . . . . . . . 12
⊢ (b ⊆ ℘1a ↔ ∃p(p ⊆ a ∧ b = ℘1p)) | 
| 19 |   | vex 2863 | 
. . . . . . . . . . . . 13
⊢ g ∈
V | 
| 20 | 19 | sspw1 4336 | 
. . . . . . . . . . . 12
⊢ (g ⊆ ℘1a ↔ ∃q(q ⊆ a ∧ g = ℘1q)) | 
| 21 | 18, 20 | anbi12i 678 | 
. . . . . . . . . . 11
⊢ ((b ⊆ ℘1a ∧ g ⊆ ℘1a) ↔ (∃p(p ⊆ a ∧ b = ℘1p) ∧ ∃q(q ⊆ a ∧ g = ℘1q))) | 
| 22 |   | eeanv 1913 | 
. . . . . . . . . . 11
⊢ (∃p∃q((p ⊆ a ∧ b = ℘1p) ∧ (q ⊆ a ∧ g = ℘1q)) ↔ (∃p(p ⊆ a ∧ b = ℘1p) ∧ ∃q(q ⊆ a ∧ g = ℘1q))) | 
| 23 | 21, 22 | bitr4i 243 | 
. . . . . . . . . 10
⊢ ((b ⊆ ℘1a ∧ g ⊆ ℘1a) ↔ ∃p∃q((p ⊆ a ∧ b = ℘1p) ∧ (q ⊆ a ∧ g = ℘1q))) | 
| 24 | 16, 23 | sylib 188 | 
. . . . . . . . 9
⊢ (℘1a = (b ∪
g) → ∃p∃q((p ⊆ a ∧ b = ℘1p) ∧ (q ⊆ a ∧ g = ℘1q))) | 
| 25 |   | pw1eq 4144 | 
. . . . . . . . . . . . . . . . 17
⊢ (a = p →
℘1a = ℘1p) | 
| 26 | 25 | eleq1d 2419 | 
. . . . . . . . . . . . . . . 16
⊢ (a = p →
(℘1a ∈ Nc ℘1p ↔ ℘1p ∈ Nc ℘1p)) | 
| 27 |   | vex 2863 | 
. . . . . . . . . . . . . . . . . 18
⊢ p ∈
V | 
| 28 | 27 | pw1ex 4304 | 
. . . . . . . . . . . . . . . . 17
⊢ ℘1p ∈
V | 
| 29 | 28 | ncid 6124 | 
. . . . . . . . . . . . . . . 16
⊢ ℘1p ∈ Nc ℘1p | 
| 30 | 26, 29 | speiv 2000 | 
. . . . . . . . . . . . . . 15
⊢ ∃a℘1a ∈ Nc ℘1p | 
| 31 |   | ncelncs 6121 | 
. . . . . . . . . . . . . . . 16
⊢ (℘1p ∈ V → Nc ℘1p ∈ NC ) | 
| 32 |   | ce0nnul 6178 | 
. . . . . . . . . . . . . . . 16
⊢ ( Nc ℘1p ∈ NC → (( Nc ℘1p ↑c 0c)
≠ ∅ ↔ ∃a℘1a ∈ Nc ℘1p)) | 
| 33 | 28, 31, 32 | mp2b 9 | 
. . . . . . . . . . . . . . 15
⊢ (( Nc ℘1p ↑c 0c)
≠ ∅ ↔ ∃a℘1a ∈ Nc ℘1p) | 
| 34 | 30, 33 | mpbir 200 | 
. . . . . . . . . . . . . 14
⊢ ( Nc ℘1p ↑c 0c)
≠ ∅ | 
| 35 |   | pw1eq 4144 | 
. . . . . . . . . . . . . . . . 17
⊢ (a = q →
℘1a = ℘1q) | 
| 36 | 35 | eleq1d 2419 | 
. . . . . . . . . . . . . . . 16
⊢ (a = q →
(℘1a ∈ Nc ℘1q ↔ ℘1q ∈ Nc ℘1q)) | 
| 37 |   | vex 2863 | 
. . . . . . . . . . . . . . . . . 18
⊢ q ∈
V | 
| 38 | 37 | pw1ex 4304 | 
. . . . . . . . . . . . . . . . 17
⊢ ℘1q ∈
V | 
| 39 | 38 | ncid 6124 | 
. . . . . . . . . . . . . . . 16
⊢ ℘1q ∈ Nc ℘1q | 
| 40 | 36, 39 | speiv 2000 | 
. . . . . . . . . . . . . . 15
⊢ ∃a℘1a ∈ Nc ℘1q | 
| 41 |   | ncelncs 6121 | 
. . . . . . . . . . . . . . . 16
⊢ (℘1q ∈ V → Nc ℘1q ∈ NC ) | 
| 42 |   | ce0nnul 6178 | 
. . . . . . . . . . . . . . . 16
⊢ ( Nc ℘1q ∈ NC → (( Nc ℘1q ↑c 0c)
≠ ∅ ↔ ∃a℘1a ∈ Nc ℘1q)) | 
| 43 | 38, 41, 42 | mp2b 9 | 
. . . . . . . . . . . . . . 15
⊢ (( Nc ℘1q ↑c 0c)
≠ ∅ ↔ ∃a℘1a ∈ Nc ℘1q) | 
| 44 | 40, 43 | mpbir 200 | 
. . . . . . . . . . . . . 14
⊢ ( Nc ℘1q ↑c 0c)
≠ ∅ | 
| 45 | 34, 44 | pm3.2i 441 | 
. . . . . . . . . . . . 13
⊢ (( Nc ℘1p ↑c 0c)
≠ ∅ ∧ (
Nc ℘1q ↑c 0c)
≠ ∅) | 
| 46 |   | nceq 6109 | 
. . . . . . . . . . . . . . . 16
⊢ (b = ℘1p → Nc b = Nc ℘1p) | 
| 47 | 46 | oveq1d 5538 | 
. . . . . . . . . . . . . . 15
⊢ (b = ℘1p → ( Nc b ↑c 0c) =
( Nc ℘1p ↑c
0c)) | 
| 48 | 47 | neeq1d 2530 | 
. . . . . . . . . . . . . 14
⊢ (b = ℘1p → (( Nc b ↑c 0c)
≠ ∅ ↔ ( Nc ℘1p ↑c 0c)
≠ ∅)) | 
| 49 |   | nceq 6109 | 
. . . . . . . . . . . . . . . 16
⊢ (g = ℘1q → Nc g = Nc ℘1q) | 
| 50 | 49 | oveq1d 5538 | 
. . . . . . . . . . . . . . 15
⊢ (g = ℘1q → ( Nc g ↑c 0c) =
( Nc ℘1q ↑c
0c)) | 
| 51 | 50 | neeq1d 2530 | 
. . . . . . . . . . . . . 14
⊢ (g = ℘1q → (( Nc g ↑c 0c)
≠ ∅ ↔ ( Nc ℘1q ↑c 0c)
≠ ∅)) | 
| 52 | 48, 51 | bi2anan9 843 | 
. . . . . . . . . . . . 13
⊢ ((b = ℘1p ∧ g = ℘1q) → ((( Nc
b ↑c
0c) ≠ ∅ ∧ ( Nc g ↑c 0c)
≠ ∅) ↔ (( Nc ℘1p ↑c 0c)
≠ ∅ ∧ (
Nc ℘1q ↑c 0c)
≠ ∅))) | 
| 53 | 45, 52 | mpbiri 224 | 
. . . . . . . . . . . 12
⊢ ((b = ℘1p ∧ g = ℘1q) → (( Nc
b ↑c
0c) ≠ ∅ ∧ ( Nc g ↑c 0c)
≠ ∅)) | 
| 54 | 53 | ad2ant2l 726 | 
. . . . . . . . . . 11
⊢ (((p ⊆ a ∧ b = ℘1p) ∧ (q ⊆ a ∧ g = ℘1q)) → (( Nc
b ↑c
0c) ≠ ∅ ∧ ( Nc g ↑c 0c)
≠ ∅)) | 
| 55 | 54 | a1d 22 | 
. . . . . . . . . 10
⊢ (((p ⊆ a ∧ b = ℘1p) ∧ (q ⊆ a ∧ g = ℘1q)) → ((b
∩ g) = ∅ → (( Nc
b ↑c
0c) ≠ ∅ ∧ ( Nc g ↑c 0c)
≠ ∅))) | 
| 56 | 55 | exlimivv 1635 | 
. . . . . . . . 9
⊢ (∃p∃q((p ⊆ a ∧ b = ℘1p) ∧ (q ⊆ a ∧ g = ℘1q)) → ((b
∩ g) = ∅ → (( Nc
b ↑c
0c) ≠ ∅ ∧ ( Nc g ↑c 0c)
≠ ∅))) | 
| 57 | 24, 56 | syl 15 | 
. . . . . . . 8
⊢ (℘1a = (b ∪
g) → ((b ∩ g) =
∅ → (( Nc
b ↑c
0c) ≠ ∅ ∧ ( Nc g ↑c 0c)
≠ ∅))) | 
| 58 | 57 | impcom 419 | 
. . . . . . 7
⊢ (((b ∩ g) =
∅ ∧ ℘1a = (b ∪
g)) → (( Nc b
↑c 0c) ≠ ∅ ∧ ( Nc g
↑c 0c) ≠ ∅)) | 
| 59 |   | oveq1 5531 | 
. . . . . . . . 9
⊢ (M = Nc b → (M
↑c 0c) = ( Nc b
↑c 0c)) | 
| 60 | 59 | neeq1d 2530 | 
. . . . . . . 8
⊢ (M = Nc b → ((M
↑c 0c) ≠ ∅ ↔ ( Nc
b ↑c
0c) ≠ ∅)) | 
| 61 |   | oveq1 5531 | 
. . . . . . . . 9
⊢ (N = Nc g → (N
↑c 0c) = ( Nc g
↑c 0c)) | 
| 62 | 61 | neeq1d 2530 | 
. . . . . . . 8
⊢ (N = Nc g → ((N
↑c 0c) ≠ ∅ ↔ ( Nc
g ↑c
0c) ≠ ∅)) | 
| 63 | 60, 62 | bi2anan9 843 | 
. . . . . . 7
⊢ ((M = Nc b ∧ N = Nc g) → (((M
↑c 0c) ≠ ∅ ∧ (N ↑c 0c)
≠ ∅) ↔ (( Nc b
↑c 0c) ≠ ∅ ∧ ( Nc g
↑c 0c) ≠ ∅))) | 
| 64 | 58, 63 | syl5ibr 212 | 
. . . . . 6
⊢ ((M = Nc b ∧ N = Nc g) → (((b
∩ g) = ∅ ∧ ℘1a = (b ∪
g)) → ((M ↑c 0c)
≠ ∅ ∧
(N ↑c
0c) ≠ ∅))) | 
| 65 | 10, 64 | syl 15 | 
. . . . 5
⊢ (((M ∈ NC ∧ N ∈ NC ) ∧ (b ∈ M ∧ g ∈ N)) → (((b
∩ g) = ∅ ∧ ℘1a = (b ∪
g)) → ((M ↑c 0c)
≠ ∅ ∧
(N ↑c
0c) ≠ ∅))) | 
| 66 | 65 | rexlimdvva 2746 | 
. . . 4
⊢ ((M ∈ NC ∧ N ∈ NC ) → (∃b ∈ M ∃g ∈ N ((b ∩ g) =
∅ ∧ ℘1a = (b ∪
g)) → ((M ↑c 0c)
≠ ∅ ∧
(N ↑c
0c) ≠ ∅))) | 
| 67 | 66 | exlimdv 1636 | 
. . 3
⊢ ((M ∈ NC ∧ N ∈ NC ) → (∃a∃b ∈ M ∃g ∈ N ((b ∩ g) =
∅ ∧ ℘1a = (b ∪
g)) → ((M ↑c 0c)
≠ ∅ ∧
(N ↑c
0c) ≠ ∅))) | 
| 68 | 6, 67 | sylbid 206 | 
. 2
⊢ ((M ∈ NC ∧ N ∈ NC ) → (((M
+c N)
↑c 0c) ≠ ∅ → ((M
↑c 0c) ≠ ∅ ∧ (N ↑c 0c)
≠ ∅))) | 
| 69 |   | ce0nnul 6178 | 
. . . . 5
⊢ (M ∈ NC → ((M
↑c 0c) ≠ ∅ ↔ ∃b℘1b ∈ M)) | 
| 70 |   | ce0nnul 6178 | 
. . . . 5
⊢ (N ∈ NC → ((N
↑c 0c) ≠ ∅ ↔ ∃g℘1g ∈ N)) | 
| 71 | 69, 70 | bi2anan9 843 | 
. . . 4
⊢ ((M ∈ NC ∧ N ∈ NC ) → (((M
↑c 0c) ≠ ∅ ∧ (N ↑c 0c)
≠ ∅) ↔ (∃b℘1b ∈ M ∧ ∃g℘1g ∈ N))) | 
| 72 |   | eeanv 1913 | 
. . . 4
⊢ (∃b∃g(℘1b ∈ M ∧ ℘1g ∈ N) ↔ (∃b℘1b ∈ M ∧ ∃g℘1g ∈ N)) | 
| 73 | 71, 72 | syl6bbr 254 | 
. . 3
⊢ ((M ∈ NC ∧ N ∈ NC ) → (((M
↑c 0c) ≠ ∅ ∧ (N ↑c 0c)
≠ ∅) ↔ ∃b∃g(℘1b ∈ M ∧ ℘1g ∈ N))) | 
| 74 |   | ncseqnc 6129 | 
. . . . . 6
⊢ (M ∈ NC → (M = Nc ℘1b ↔ ℘1b ∈ M)) | 
| 75 |   | ncseqnc 6129 | 
. . . . . 6
⊢ (N ∈ NC → (N = Nc ℘1g ↔ ℘1g ∈ N)) | 
| 76 | 74, 75 | bi2anan9 843 | 
. . . . 5
⊢ ((M ∈ NC ∧ N ∈ NC ) → ((M =
Nc ℘1b ∧ N = Nc ℘1g) ↔ (℘1b ∈ M ∧ ℘1g ∈ N))) | 
| 77 |   | vvex 4110 | 
. . . . . . . . . . . 12
⊢ V ∈ V | 
| 78 | 17, 77 | xpsnen 6050 | 
. . . . . . . . . . 11
⊢ (b × {V}) ≈ b | 
| 79 |   | enpw1 6063 | 
. . . . . . . . . . 11
⊢ ((b × {V}) ≈ b ↔ ℘1(b × {V}) ≈ ℘1b) | 
| 80 | 78, 79 | mpbi 199 | 
. . . . . . . . . 10
⊢ ℘1(b × {V}) ≈ ℘1b | 
| 81 |   | snex 4112 | 
. . . . . . . . . . . . 13
⊢ {V} ∈ V | 
| 82 | 17, 81 | xpex 5116 | 
. . . . . . . . . . . 12
⊢ (b × {V}) ∈
V | 
| 83 | 82 | pw1ex 4304 | 
. . . . . . . . . . 11
⊢ ℘1(b × {V}) ∈
V | 
| 84 | 83 | eqnc 6128 | 
. . . . . . . . . 10
⊢ ( Nc ℘1(b × {V}) = Nc
℘1b ↔ ℘1(b × {V}) ≈ ℘1b) | 
| 85 | 80, 84 | mpbir 200 | 
. . . . . . . . 9
⊢  Nc ℘1(b × {V}) = Nc
℘1b | 
| 86 |   | 0ex 4111 | 
. . . . . . . . . . . 12
⊢ ∅ ∈
V | 
| 87 | 19, 86 | xpsnen 6050 | 
. . . . . . . . . . 11
⊢ (g × {∅})
≈ g | 
| 88 |   | enpw1 6063 | 
. . . . . . . . . . 11
⊢ ((g × {∅})
≈ g ↔ ℘1(g × {∅})
≈ ℘1g) | 
| 89 | 87, 88 | mpbi 199 | 
. . . . . . . . . 10
⊢ ℘1(g × {∅})
≈ ℘1g | 
| 90 |   | snex 4112 | 
. . . . . . . . . . . . 13
⊢ {∅} ∈
V | 
| 91 | 19, 90 | xpex 5116 | 
. . . . . . . . . . . 12
⊢ (g × {∅})
∈ V | 
| 92 | 91 | pw1ex 4304 | 
. . . . . . . . . . 11
⊢ ℘1(g × {∅})
∈ V | 
| 93 | 92 | eqnc 6128 | 
. . . . . . . . . 10
⊢ ( Nc ℘1(g × {∅}) =
Nc ℘1g ↔ ℘1(g × {∅})
≈ ℘1g) | 
| 94 | 89, 93 | mpbir 200 | 
. . . . . . . . 9
⊢  Nc ℘1(g × {∅}) =
Nc ℘1g | 
| 95 | 85, 94 | addceq12i 4389 | 
. . . . . . . 8
⊢ ( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅})) =
( Nc ℘1b +c Nc ℘1g) | 
| 96 | 95 | oveq1i 5534 | 
. . . . . . 7
⊢ (( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅}))
↑c 0c) = (( Nc ℘1b +c Nc ℘1g) ↑c
0c) | 
| 97 |   | pw1un 4164 | 
. . . . . . . . . 10
⊢ ℘1((b × {V}) ∪ (g × {∅})) =
(℘1(b × {V}) ∪ ℘1(g × {∅})) | 
| 98 | 83 | ncid 6124 | 
. . . . . . . . . . 11
⊢ ℘1(b × {V}) ∈
Nc ℘1(b × {V}) | 
| 99 | 92 | ncid 6124 | 
. . . . . . . . . . 11
⊢ ℘1(g × {∅})
∈ Nc ℘1(g × {∅}) | 
| 100 |   | vn0 3558 | 
. . . . . . . . . . . . . 14
⊢ V ≠ ∅ | 
| 101 | 77, 100 | xpnedisj 5514 | 
. . . . . . . . . . . . 13
⊢ ((b × {V}) ∩ (g × {∅})) =
∅ | 
| 102 |   | pw1eq 4144 | 
. . . . . . . . . . . . 13
⊢ (((b × {V}) ∩ (g × {∅})) =
∅ → ℘1((b × {V}) ∩ (g × {∅})) =
℘1∅) | 
| 103 | 101, 102 | ax-mp 5 | 
. . . . . . . . . . . 12
⊢ ℘1((b × {V}) ∩ (g × {∅})) =
℘1∅ | 
| 104 |   | pw1in 4165 | 
. . . . . . . . . . . 12
⊢ ℘1((b × {V}) ∩ (g × {∅})) =
(℘1(b × {V}) ∩ ℘1(g × {∅})) | 
| 105 |   | pw10 4162 | 
. . . . . . . . . . . 12
⊢ ℘1∅
= ∅ | 
| 106 | 103, 104,
105 | 3eqtr3i 2381 | 
. . . . . . . . . . 11
⊢ (℘1(b × {V}) ∩ ℘1(g × {∅})) =
∅ | 
| 107 |   | eladdci 4400 | 
. . . . . . . . . . 11
⊢ ((℘1(b × {V}) ∈
Nc ℘1(b × {V}) ∧
℘1(g × {∅})
∈ Nc ℘1(g × {∅})
∧ (℘1(b × {V}) ∩ ℘1(g × {∅})) =
∅) → (℘1(b × {V}) ∪ ℘1(g × {∅}))
∈ ( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅}))) | 
| 108 | 98, 99, 106, 107 | mp3an 1277 | 
. . . . . . . . . 10
⊢ (℘1(b × {V}) ∪ ℘1(g × {∅}))
∈ ( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅})) | 
| 109 | 97, 108 | eqeltri 2423 | 
. . . . . . . . 9
⊢ ℘1((b × {V}) ∪ (g × {∅}))
∈ ( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅})) | 
| 110 | 82, 91 | unex 4107 | 
. . . . . . . . . 10
⊢ ((b × {V}) ∪ (g × {∅}))
∈ V | 
| 111 |   | pw1eq 4144 | 
. . . . . . . . . . 11
⊢ (a = ((b ×
{V}) ∪ (g × {∅})) → ℘1a = ℘1((b × {V}) ∪ (g × {∅}))) | 
| 112 | 111 | eleq1d 2419 | 
. . . . . . . . . 10
⊢ (a = ((b ×
{V}) ∪ (g × {∅})) → (℘1a ∈ ( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅}))
↔ ℘1((b × {V}) ∪ (g × {∅}))
∈ ( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅})))) | 
| 113 | 110, 112 | spcev 2947 | 
. . . . . . . . 9
⊢ (℘1((b × {V}) ∪ (g × {∅}))
∈ ( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅}))
→ ∃a℘1a ∈ ( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅}))) | 
| 114 | 109, 113 | ax-mp 5 | 
. . . . . . . 8
⊢ ∃a℘1a ∈ ( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅})) | 
| 115 | 83 | ncelncsi 6122 | 
. . . . . . . . . 10
⊢  Nc ℘1(b × {V}) ∈
NC | 
| 116 | 92 | ncelncsi 6122 | 
. . . . . . . . . 10
⊢  Nc ℘1(g × {∅})
∈ NC | 
| 117 |   | ncaddccl 6145 | 
. . . . . . . . . 10
⊢ (( Nc ℘1(b × {V}) ∈
NC ∧ Nc ℘1(g × {∅})
∈ NC ) → (
Nc ℘1(b × {V}) +c Nc ℘1(g × {∅}))
∈ NC
) | 
| 118 | 115, 116,
117 | mp2an 653 | 
. . . . . . . . 9
⊢ ( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅}))
∈ NC | 
| 119 |   | ce0nnul 6178 | 
. . . . . . . . 9
⊢ (( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅}))
∈ NC → (((
Nc ℘1(b × {V}) +c Nc ℘1(g × {∅}))
↑c 0c) ≠ ∅ ↔ ∃a℘1a ∈ ( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅})))) | 
| 120 | 118, 119 | ax-mp 5 | 
. . . . . . . 8
⊢ ((( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅}))
↑c 0c) ≠ ∅ ↔ ∃a℘1a ∈ ( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅}))) | 
| 121 | 114, 120 | mpbir 200 | 
. . . . . . 7
⊢ (( Nc ℘1(b × {V}) +c Nc ℘1(g × {∅}))
↑c 0c) ≠ ∅ | 
| 122 | 96, 121 | eqnetrri 2536 | 
. . . . . 6
⊢ (( Nc ℘1b +c Nc ℘1g) ↑c 0c)
≠ ∅ | 
| 123 |   | addceq12 4386 | 
. . . . . . . 8
⊢ ((M = Nc ℘1b ∧ N = Nc ℘1g) → (M
+c N) = ( Nc ℘1b +c Nc ℘1g)) | 
| 124 | 123 | oveq1d 5538 | 
. . . . . . 7
⊢ ((M = Nc ℘1b ∧ N = Nc ℘1g) → ((M
+c N)
↑c 0c) = (( Nc ℘1b +c Nc ℘1g) ↑c
0c)) | 
| 125 | 124 | neeq1d 2530 | 
. . . . . 6
⊢ ((M = Nc ℘1b ∧ N = Nc ℘1g) → (((M
+c N)
↑c 0c) ≠ ∅ ↔ (( Nc ℘1b +c Nc ℘1g) ↑c 0c)
≠ ∅)) | 
| 126 | 122, 125 | mpbiri 224 | 
. . . . 5
⊢ ((M = Nc ℘1b ∧ N = Nc ℘1g) → ((M
+c N)
↑c 0c) ≠ ∅) | 
| 127 | 76, 126 | syl6bir 220 | 
. . . 4
⊢ ((M ∈ NC ∧ N ∈ NC ) → ((℘1b ∈ M ∧ ℘1g ∈ N) → ((M
+c N)
↑c 0c) ≠ ∅)) | 
| 128 | 127 | exlimdvv 1637 | 
. . 3
⊢ ((M ∈ NC ∧ N ∈ NC ) → (∃b∃g(℘1b ∈ M ∧ ℘1g ∈ N) → ((M
+c N)
↑c 0c) ≠ ∅)) | 
| 129 | 73, 128 | sylbid 206 | 
. 2
⊢ ((M ∈ NC ∧ N ∈ NC ) → (((M
↑c 0c) ≠ ∅ ∧ (N ↑c 0c)
≠ ∅) → ((M +c N) ↑c 0c)
≠ ∅)) | 
| 130 | 68, 129 | impbid 183 | 
1
⊢ ((M ∈ NC ∧ N ∈ NC ) → (((M
+c N)
↑c 0c) ≠ ∅ ↔ ((M
↑c 0c) ≠ ∅ ∧ (N ↑c 0c)
≠ ∅))) |