| Step | Hyp | Ref
 | Expression | 
| 1 |   | tccl 6161 | 
. . . 4
⊢ (N ∈ NC → Tc
N ∈ NC ) | 
| 2 |   | dflec2 6211 | 
. . . 4
⊢ ((M ∈ NC ∧ Tc N
∈ NC ) →
(M ≤c Tc N
↔ ∃q ∈ NC Tc N = (M
+c q))) | 
| 3 | 1, 2 | sylan2 460 | 
. . 3
⊢ ((M ∈ NC ∧ N ∈ NC ) → (M
≤c Tc N ↔ ∃q ∈ NC Tc N =
(M +c q))) | 
| 4 |   | elncs 6120 | 
. . . . . . . 8
⊢ (M ∈ NC ↔ ∃a M = Nc a) | 
| 5 |   | elncs 6120 | 
. . . . . . . 8
⊢ (N ∈ NC ↔ ∃b N = Nc b) | 
| 6 |   | elncs 6120 | 
. . . . . . . 8
⊢ (q ∈ NC ↔ ∃c q = Nc c) | 
| 7 | 4, 5, 6 | 3anbi123i 1140 | 
. . . . . . 7
⊢ ((M ∈ NC ∧ N ∈ NC ∧ q ∈ NC ) ↔ (∃a M = Nc a ∧ ∃b N = Nc b ∧ ∃c q = Nc c)) | 
| 8 |   | eeeanv 1914 | 
. . . . . . 7
⊢ (∃a∃b∃c(M = Nc a ∧ N = Nc b ∧ q = Nc c) ↔ (∃a M = Nc a ∧ ∃b N = Nc b ∧ ∃c q = Nc c)) | 
| 9 | 7, 8 | bitr4i 243 | 
. . . . . 6
⊢ ((M ∈ NC ∧ N ∈ NC ∧ q ∈ NC ) ↔ ∃a∃b∃c(M = Nc a ∧ N = Nc b ∧ q = Nc c)) | 
| 10 |   | eqcom 2355 | 
. . . . . . . . . . 11
⊢ ( Nc ℘1b = ( Nc a +c Nc c) ↔ ( Nc a
+c Nc c) = Nc ℘1b) | 
| 11 |   | vex 2863 | 
. . . . . . . . . . . . . 14
⊢ a ∈
V | 
| 12 | 11 | ncelncsi 6122 | 
. . . . . . . . . . . . 13
⊢  Nc a ∈ NC | 
| 13 |   | vex 2863 | 
. . . . . . . . . . . . . 14
⊢ c ∈
V | 
| 14 | 13 | ncelncsi 6122 | 
. . . . . . . . . . . . 13
⊢  Nc c ∈ NC | 
| 15 |   | ncaddccl 6145 | 
. . . . . . . . . . . . 13
⊢ (( Nc a ∈ NC ∧ Nc c ∈ NC ) → ( Nc a +c Nc c) ∈ NC
) | 
| 16 | 12, 14, 15 | mp2an 653 | 
. . . . . . . . . . . 12
⊢ ( Nc a
+c Nc c) ∈ NC | 
| 17 |   | ncseqnc 6129 | 
. . . . . . . . . . . 12
⊢ (( Nc a
+c Nc c) ∈ NC → (( Nc a +c Nc c) = Nc ℘1b ↔ ℘1b ∈ ( Nc a
+c Nc c))) | 
| 18 | 16, 17 | ax-mp 5 | 
. . . . . . . . . . 11
⊢ (( Nc a
+c Nc c) = Nc ℘1b ↔ ℘1b ∈ ( Nc a
+c Nc c)) | 
| 19 | 10, 18 | bitri 240 | 
. . . . . . . . . 10
⊢ ( Nc ℘1b = ( Nc a +c Nc c) ↔ ℘1b ∈ ( Nc a
+c Nc c)) | 
| 20 |   | eladdc 4399 | 
. . . . . . . . . . 11
⊢ (℘1b ∈ ( Nc a
+c Nc c) ↔ ∃x ∈ Nc a∃y ∈ Nc c((x ∩ y) =
∅ ∧ ℘1b = (x ∪
y))) | 
| 21 |   | vex 2863 | 
. . . . . . . . . . . . . . 15
⊢ x ∈
V | 
| 22 |   | vex 2863 | 
. . . . . . . . . . . . . . 15
⊢ y ∈
V | 
| 23 | 21, 22 | pw1equn 4332 | 
. . . . . . . . . . . . . 14
⊢ (℘1b = (x ∪
y) ↔ ∃n∃m(b = (n ∪
m) ∧
x = ℘1n ∧ y = ℘1m)) | 
| 24 |   | eleq1 2413 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ (x = ℘1n → (x
∈ Nc a ↔ ℘1n ∈ Nc a)) | 
| 25 |   | eleq1 2413 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ (y = ℘1m → (y
∈ Nc c ↔ ℘1m ∈ Nc c)) | 
| 26 | 24, 25 | bi2anan9 843 | 
. . . . . . . . . . . . . . . . . . 19
⊢ ((x = ℘1n ∧ y = ℘1m) → ((x
∈ Nc a ∧ y ∈ Nc c) ↔ (℘1n ∈ Nc a ∧ ℘1m ∈ Nc c))) | 
| 27 |   | ineq12 3453 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ ((x = ℘1n ∧ y = ℘1m) → (x
∩ y) = (℘1n ∩ ℘1m)) | 
| 28 | 27 | eqeq1d 2361 | 
. . . . . . . . . . . . . . . . . . 19
⊢ ((x = ℘1n ∧ y = ℘1m) → ((x
∩ y) = ∅ ↔ (℘1n ∩ ℘1m) = ∅)) | 
| 29 | 26, 28 | anbi12d 691 | 
. . . . . . . . . . . . . . . . . 18
⊢ ((x = ℘1n ∧ y = ℘1m) → (((x
∈ Nc a ∧ y ∈ Nc c) ∧ (x ∩
y) = ∅)
↔ ((℘1n ∈ Nc a ∧ ℘1m ∈ Nc c) ∧ (℘1n ∩ ℘1m) = ∅))) | 
| 30 |   | ncseqnc 6129 | 
. . . . . . . . . . . . . . . . . . . . 21
⊢ ( Nc a ∈ NC → ( Nc a = Nc ℘1n ↔ ℘1n ∈ Nc a)) | 
| 31 | 12, 30 | ax-mp 5 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ ( Nc a = Nc ℘1n ↔ ℘1n ∈ Nc a) | 
| 32 |   | vex 2863 | 
. . . . . . . . . . . . . . . . . . . . . 22
⊢ n ∈
V | 
| 33 | 32 | ncelncsi 6122 | 
. . . . . . . . . . . . . . . . . . . . 21
⊢  Nc n ∈ NC | 
| 34 |   | tceq 6159 | 
. . . . . . . . . . . . . . . . . . . . . . . 24
⊢ (p = Nc n → Tc
p = Tc Nc n) | 
| 35 | 32 | tcnc 6226 | 
. . . . . . . . . . . . . . . . . . . . . . . 24
⊢  Tc Nc n = Nc ℘1n | 
| 36 | 34, 35 | syl6eq 2401 | 
. . . . . . . . . . . . . . . . . . . . . . 23
⊢ (p = Nc n → Tc
p = Nc ℘1n) | 
| 37 | 36 | eqeq2d 2364 | 
. . . . . . . . . . . . . . . . . . . . . 22
⊢ (p = Nc n → ( Nc a = Tc
p ↔ Nc
a = Nc ℘1n)) | 
| 38 | 37 | rspcev 2956 | 
. . . . . . . . . . . . . . . . . . . . 21
⊢ (( Nc n ∈ NC ∧ Nc a = Nc ℘1n) → ∃p ∈ NC Nc a = Tc p) | 
| 39 | 33, 38 | mpan 651 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ ( Nc a = Nc ℘1n → ∃p ∈ NC Nc a = Tc p) | 
| 40 | 31, 39 | sylbir 204 | 
. . . . . . . . . . . . . . . . . . 19
⊢ (℘1n ∈ Nc a → ∃p ∈ NC Nc a = Tc p) | 
| 41 | 40 | ad2antrr 706 | 
. . . . . . . . . . . . . . . . . 18
⊢ (((℘1n ∈ Nc a ∧ ℘1m ∈ Nc c) ∧ (℘1n ∩ ℘1m) = ∅) →
∃p ∈ NC Nc a = Tc p) | 
| 42 | 29, 41 | syl6bi 219 | 
. . . . . . . . . . . . . . . . 17
⊢ ((x = ℘1n ∧ y = ℘1m) → (((x
∈ Nc a ∧ y ∈ Nc c) ∧ (x ∩
y) = ∅)
→ ∃p ∈ NC Nc a = Tc
p)) | 
| 43 | 42 | 3adant1 973 | 
. . . . . . . . . . . . . . . 16
⊢ ((b = (n ∪
m) ∧
x = ℘1n ∧ y = ℘1m) → (((x
∈ Nc a ∧ y ∈ Nc c) ∧ (x ∩
y) = ∅)
→ ∃p ∈ NC Nc a = Tc
p)) | 
| 44 | 43 | exlimivv 1635 | 
. . . . . . . . . . . . . . 15
⊢ (∃n∃m(b = (n ∪
m) ∧
x = ℘1n ∧ y = ℘1m) → (((x
∈ Nc a ∧ y ∈ Nc c) ∧ (x ∩
y) = ∅)
→ ∃p ∈ NC Nc a = Tc
p)) | 
| 45 | 44 | com12 27 | 
. . . . . . . . . . . . . 14
⊢ (((x ∈ Nc a ∧ y ∈ Nc c) ∧ (x ∩ y) =
∅) → (∃n∃m(b = (n ∪
m) ∧
x = ℘1n ∧ y = ℘1m) → ∃p ∈ NC Nc a = Tc p)) | 
| 46 | 23, 45 | syl5bi 208 | 
. . . . . . . . . . . . 13
⊢ (((x ∈ Nc a ∧ y ∈ Nc c) ∧ (x ∩ y) =
∅) → (℘1b = (x ∪
y) → ∃p ∈ NC Nc a = Tc p)) | 
| 47 | 46 | expimpd 586 | 
. . . . . . . . . . . 12
⊢ ((x ∈ Nc a ∧ y ∈ Nc c) → (((x
∩ y) = ∅ ∧ ℘1b = (x ∪
y)) → ∃p ∈ NC Nc a = Tc p)) | 
| 48 | 47 | rexlimivv 2744 | 
. . . . . . . . . . 11
⊢ (∃x ∈ Nc a∃y ∈ Nc c((x ∩ y) =
∅ ∧ ℘1b = (x ∪
y)) → ∃p ∈ NC Nc a = Tc p) | 
| 49 | 20, 48 | sylbi 187 | 
. . . . . . . . . 10
⊢ (℘1b ∈ ( Nc a
+c Nc c) → ∃p ∈ NC Nc a = Tc p) | 
| 50 | 19, 49 | sylbi 187 | 
. . . . . . . . 9
⊢ ( Nc ℘1b = ( Nc a +c Nc c) → ∃p ∈ NC Nc a = Tc p) | 
| 51 |   | tceq 6159 | 
. . . . . . . . . . . . 13
⊢ (N = Nc b → Tc
N = Tc Nc b) | 
| 52 |   | vex 2863 | 
. . . . . . . . . . . . . 14
⊢ b ∈
V | 
| 53 | 52 | tcnc 6226 | 
. . . . . . . . . . . . 13
⊢  Tc Nc b = Nc ℘1b | 
| 54 | 51, 53 | syl6eq 2401 | 
. . . . . . . . . . . 12
⊢ (N = Nc b → Tc
N = Nc ℘1b) | 
| 55 | 54 | 3ad2ant2 977 | 
. . . . . . . . . . 11
⊢ ((M = Nc a ∧ N = Nc b ∧ q = Nc c) → Tc
N = Nc ℘1b) | 
| 56 |   | addceq12 4386 | 
. . . . . . . . . . . 12
⊢ ((M = Nc a ∧ q = Nc c) → (M
+c q) = ( Nc a
+c Nc c)) | 
| 57 | 56 | 3adant2 974 | 
. . . . . . . . . . 11
⊢ ((M = Nc a ∧ N = Nc b ∧ q = Nc c) → (M
+c q) = ( Nc a
+c Nc c)) | 
| 58 | 55, 57 | eqeq12d 2367 | 
. . . . . . . . . 10
⊢ ((M = Nc a ∧ N = Nc b ∧ q = Nc c) → ( Tc N =
(M +c q) ↔ Nc ℘1b = ( Nc a +c Nc c))) | 
| 59 |   | eqeq1 2359 | 
. . . . . . . . . . . 12
⊢ (M = Nc a → (M =
Tc p ↔ Nc a = Tc
p)) | 
| 60 | 59 | rexbidv 2636 | 
. . . . . . . . . . 11
⊢ (M = Nc a → (∃p ∈ NC M = Tc
p ↔ ∃p ∈ NC Nc a = Tc p)) | 
| 61 | 60 | 3ad2ant1 976 | 
. . . . . . . . . 10
⊢ ((M = Nc a ∧ N = Nc b ∧ q = Nc c) → (∃p ∈ NC M = Tc
p ↔ ∃p ∈ NC Nc a = Tc p)) | 
| 62 | 58, 61 | imbi12d 311 | 
. . . . . . . . 9
⊢ ((M = Nc a ∧ N = Nc b ∧ q = Nc c) → (( Tc N =
(M +c q) → ∃p ∈ NC M = Tc
p) ↔ ( Nc
℘1b = ( Nc a +c Nc c) → ∃p ∈ NC Nc a = Tc p))) | 
| 63 | 50, 62 | mpbiri 224 | 
. . . . . . . 8
⊢ ((M = Nc a ∧ N = Nc b ∧ q = Nc c) → ( Tc N =
(M +c q) → ∃p ∈ NC M = Tc
p)) | 
| 64 | 63 | exlimiv 1634 | 
. . . . . . 7
⊢ (∃c(M = Nc a ∧ N = Nc b ∧ q = Nc c) → ( Tc N =
(M +c q) → ∃p ∈ NC M = Tc
p)) | 
| 65 | 64 | exlimivv 1635 | 
. . . . . 6
⊢ (∃a∃b∃c(M = Nc a ∧ N = Nc b ∧ q = Nc c) → ( Tc N =
(M +c q) → ∃p ∈ NC M = Tc
p)) | 
| 66 | 9, 65 | sylbi 187 | 
. . . . 5
⊢ ((M ∈ NC ∧ N ∈ NC ∧ q ∈ NC ) → ( Tc
N = (M
+c q) → ∃p ∈ NC M = Tc
p)) | 
| 67 | 66 | 3expa 1151 | 
. . . 4
⊢ (((M ∈ NC ∧ N ∈ NC ) ∧ q ∈ NC ) → ( Tc
N = (M
+c q) → ∃p ∈ NC M = Tc
p)) | 
| 68 | 67 | rexlimdva 2739 | 
. . 3
⊢ ((M ∈ NC ∧ N ∈ NC ) → (∃q ∈ NC Tc N =
(M +c q) → ∃p ∈ NC M = Tc
p)) | 
| 69 | 3, 68 | sylbid 206 | 
. 2
⊢ ((M ∈ NC ∧ N ∈ NC ) → (M
≤c Tc N → ∃p ∈ NC M = Tc
p)) | 
| 70 | 69 | 3impia 1148 | 
1
⊢ ((M ∈ NC ∧ N ∈ NC ∧ M ≤c Tc N)
→ ∃p ∈ NC M = Tc p) |