Detailed syntax breakdown of Definition df-nlfn
| Step | Hyp | Ref
| Expression |
| 1 | | cnl 8760 |
. 2
class null |
| 2 | | chil 8727 |
. . . . 5
class ℋ |
| 3 | | cc 5212 |
. . . . 5
class ℂ |
| 4 | | vt |
. . . . . 6
set t |
| 5 | 4 | cv 953 |
. . . . 5
class t |
| 6 | 2, 3, 5 | wf 3173 |
. . . 4
wff t: ℋ
–→ℂ |
| 7 | | vy |
. . . . . 6
set y |
| 8 | 7 | cv 953 |
. . . . 5
class y |
| 9 | | vx |
. . . . . . . . 9
set x |
| 10 | 9 | cv 953 |
. . . . . . . 8
class x |
| 11 | 10, 5 | cfv 3177 |
. . . . . . 7
class (t
‘x) |
| 12 | | cc0 5214 |
. . . . . . 7
class 0 |
| 13 | 11, 12 | wceq 954 |
. . . . . 6
wff (t
‘x) = 0 |
| 14 | 13, 9, 2 | crab 1645 |
. . . . 5
class {x
∈ ℋ ∣(t ‘x) = 0} |
| 15 | 8, 14 | wceq 954 |
. . . 4
wff y =
{x ∈ ℋ ∣(t ‘x) =
0} |
| 16 | 6, 15 | wa 223 |
. . 3
wff (t:
ℋ –→ℂ ⋀ y =
{x ∈ ℋ ∣(t ‘x) =
0}) |
| 17 | 16, 4, 7 | copab 2661 |
. 2
class {〈t, y〉∣(t: ℋ –→ℂ ⋀ y = {x ∈
ℋ ∣(t ‘x) = 0})} |
| 18 | 1, 17 | wceq 954 |
1
wff null = {〈t, y〉∣(t: ℋ –→ℂ ⋀ y = {x ∈
ℋ ∣(t ‘x) = 0})} |