Step |
Hyp |
Ref |
Expression |
1 |
|
itcoval0mpt.f |
⊢ 𝐹 = ( 𝑛 ∈ 𝐴 ↦ 𝐵 ) |
2 |
1
|
fveq2i |
⊢ ( IterComp ‘ 𝐹 ) = ( IterComp ‘ ( 𝑛 ∈ 𝐴 ↦ 𝐵 ) ) |
3 |
2
|
fveq1i |
⊢ ( ( IterComp ‘ 𝐹 ) ‘ 0 ) = ( ( IterComp ‘ ( 𝑛 ∈ 𝐴 ↦ 𝐵 ) ) ‘ 0 ) |
4 |
|
mptexg |
⊢ ( 𝐴 ∈ 𝑉 → ( 𝑛 ∈ 𝐴 ↦ 𝐵 ) ∈ V ) |
5 |
|
itcoval0 |
⊢ ( ( 𝑛 ∈ 𝐴 ↦ 𝐵 ) ∈ V → ( ( IterComp ‘ ( 𝑛 ∈ 𝐴 ↦ 𝐵 ) ) ‘ 0 ) = ( I ↾ dom ( 𝑛 ∈ 𝐴 ↦ 𝐵 ) ) ) |
6 |
4 5
|
syl |
⊢ ( 𝐴 ∈ 𝑉 → ( ( IterComp ‘ ( 𝑛 ∈ 𝐴 ↦ 𝐵 ) ) ‘ 0 ) = ( I ↾ dom ( 𝑛 ∈ 𝐴 ↦ 𝐵 ) ) ) |
7 |
3 6
|
syl5eq |
⊢ ( 𝐴 ∈ 𝑉 → ( ( IterComp ‘ 𝐹 ) ‘ 0 ) = ( I ↾ dom ( 𝑛 ∈ 𝐴 ↦ 𝐵 ) ) ) |
8 |
|
dmmptg |
⊢ ( ∀ 𝑛 ∈ 𝐴 𝐵 ∈ 𝑊 → dom ( 𝑛 ∈ 𝐴 ↦ 𝐵 ) = 𝐴 ) |
9 |
8
|
reseq2d |
⊢ ( ∀ 𝑛 ∈ 𝐴 𝐵 ∈ 𝑊 → ( I ↾ dom ( 𝑛 ∈ 𝐴 ↦ 𝐵 ) ) = ( I ↾ 𝐴 ) ) |
10 |
|
mptresid |
⊢ ( I ↾ 𝐴 ) = ( 𝑛 ∈ 𝐴 ↦ 𝑛 ) |
11 |
9 10
|
eqtrdi |
⊢ ( ∀ 𝑛 ∈ 𝐴 𝐵 ∈ 𝑊 → ( I ↾ dom ( 𝑛 ∈ 𝐴 ↦ 𝐵 ) ) = ( 𝑛 ∈ 𝐴 ↦ 𝑛 ) ) |
12 |
7 11
|
sylan9eq |
⊢ ( ( 𝐴 ∈ 𝑉 ∧ ∀ 𝑛 ∈ 𝐴 𝐵 ∈ 𝑊 ) → ( ( IterComp ‘ 𝐹 ) ‘ 0 ) = ( 𝑛 ∈ 𝐴 ↦ 𝑛 ) ) |