| Step |
Hyp |
Ref |
Expression |
| 1 |
|
hodseq.2 |
⊢ 𝑆 : ℋ ⟶ ℋ |
| 2 |
|
hodseq.3 |
⊢ 𝑇 : ℋ ⟶ ℋ |
| 3 |
|
neg1cn |
⊢ - 1 ∈ ℂ |
| 4 |
|
homulcl |
⊢ ( ( - 1 ∈ ℂ ∧ 𝑇 : ℋ ⟶ ℋ ) → ( - 1 ·op 𝑇 ) : ℋ ⟶ ℋ ) |
| 5 |
3 2 4
|
mp2an |
⊢ ( - 1 ·op 𝑇 ) : ℋ ⟶ ℋ |
| 6 |
|
hosval |
⊢ ( ( 𝑆 : ℋ ⟶ ℋ ∧ ( - 1 ·op 𝑇 ) : ℋ ⟶ ℋ ∧ 𝑥 ∈ ℋ ) → ( ( 𝑆 +op ( - 1 ·op 𝑇 ) ) ‘ 𝑥 ) = ( ( 𝑆 ‘ 𝑥 ) +ℎ ( ( - 1 ·op 𝑇 ) ‘ 𝑥 ) ) ) |
| 7 |
1 5 6
|
mp3an12 |
⊢ ( 𝑥 ∈ ℋ → ( ( 𝑆 +op ( - 1 ·op 𝑇 ) ) ‘ 𝑥 ) = ( ( 𝑆 ‘ 𝑥 ) +ℎ ( ( - 1 ·op 𝑇 ) ‘ 𝑥 ) ) ) |
| 8 |
1
|
ffvelcdmi |
⊢ ( 𝑥 ∈ ℋ → ( 𝑆 ‘ 𝑥 ) ∈ ℋ ) |
| 9 |
2
|
ffvelcdmi |
⊢ ( 𝑥 ∈ ℋ → ( 𝑇 ‘ 𝑥 ) ∈ ℋ ) |
| 10 |
|
hvsubval |
⊢ ( ( ( 𝑆 ‘ 𝑥 ) ∈ ℋ ∧ ( 𝑇 ‘ 𝑥 ) ∈ ℋ ) → ( ( 𝑆 ‘ 𝑥 ) −ℎ ( 𝑇 ‘ 𝑥 ) ) = ( ( 𝑆 ‘ 𝑥 ) +ℎ ( - 1 ·ℎ ( 𝑇 ‘ 𝑥 ) ) ) ) |
| 11 |
8 9 10
|
syl2anc |
⊢ ( 𝑥 ∈ ℋ → ( ( 𝑆 ‘ 𝑥 ) −ℎ ( 𝑇 ‘ 𝑥 ) ) = ( ( 𝑆 ‘ 𝑥 ) +ℎ ( - 1 ·ℎ ( 𝑇 ‘ 𝑥 ) ) ) ) |
| 12 |
|
homval |
⊢ ( ( - 1 ∈ ℂ ∧ 𝑇 : ℋ ⟶ ℋ ∧ 𝑥 ∈ ℋ ) → ( ( - 1 ·op 𝑇 ) ‘ 𝑥 ) = ( - 1 ·ℎ ( 𝑇 ‘ 𝑥 ) ) ) |
| 13 |
3 2 12
|
mp3an12 |
⊢ ( 𝑥 ∈ ℋ → ( ( - 1 ·op 𝑇 ) ‘ 𝑥 ) = ( - 1 ·ℎ ( 𝑇 ‘ 𝑥 ) ) ) |
| 14 |
13
|
oveq2d |
⊢ ( 𝑥 ∈ ℋ → ( ( 𝑆 ‘ 𝑥 ) +ℎ ( ( - 1 ·op 𝑇 ) ‘ 𝑥 ) ) = ( ( 𝑆 ‘ 𝑥 ) +ℎ ( - 1 ·ℎ ( 𝑇 ‘ 𝑥 ) ) ) ) |
| 15 |
11 14
|
eqtr4d |
⊢ ( 𝑥 ∈ ℋ → ( ( 𝑆 ‘ 𝑥 ) −ℎ ( 𝑇 ‘ 𝑥 ) ) = ( ( 𝑆 ‘ 𝑥 ) +ℎ ( ( - 1 ·op 𝑇 ) ‘ 𝑥 ) ) ) |
| 16 |
7 15
|
eqtr4d |
⊢ ( 𝑥 ∈ ℋ → ( ( 𝑆 +op ( - 1 ·op 𝑇 ) ) ‘ 𝑥 ) = ( ( 𝑆 ‘ 𝑥 ) −ℎ ( 𝑇 ‘ 𝑥 ) ) ) |
| 17 |
|
hodval |
⊢ ( ( 𝑆 : ℋ ⟶ ℋ ∧ 𝑇 : ℋ ⟶ ℋ ∧ 𝑥 ∈ ℋ ) → ( ( 𝑆 −op 𝑇 ) ‘ 𝑥 ) = ( ( 𝑆 ‘ 𝑥 ) −ℎ ( 𝑇 ‘ 𝑥 ) ) ) |
| 18 |
1 2 17
|
mp3an12 |
⊢ ( 𝑥 ∈ ℋ → ( ( 𝑆 −op 𝑇 ) ‘ 𝑥 ) = ( ( 𝑆 ‘ 𝑥 ) −ℎ ( 𝑇 ‘ 𝑥 ) ) ) |
| 19 |
16 18
|
eqtr4d |
⊢ ( 𝑥 ∈ ℋ → ( ( 𝑆 +op ( - 1 ·op 𝑇 ) ) ‘ 𝑥 ) = ( ( 𝑆 −op 𝑇 ) ‘ 𝑥 ) ) |
| 20 |
19
|
rgen |
⊢ ∀ 𝑥 ∈ ℋ ( ( 𝑆 +op ( - 1 ·op 𝑇 ) ) ‘ 𝑥 ) = ( ( 𝑆 −op 𝑇 ) ‘ 𝑥 ) |
| 21 |
1 5
|
hoaddcli |
⊢ ( 𝑆 +op ( - 1 ·op 𝑇 ) ) : ℋ ⟶ ℋ |
| 22 |
1 2
|
hosubcli |
⊢ ( 𝑆 −op 𝑇 ) : ℋ ⟶ ℋ |
| 23 |
21 22
|
hoeqi |
⊢ ( ∀ 𝑥 ∈ ℋ ( ( 𝑆 +op ( - 1 ·op 𝑇 ) ) ‘ 𝑥 ) = ( ( 𝑆 −op 𝑇 ) ‘ 𝑥 ) ↔ ( 𝑆 +op ( - 1 ·op 𝑇 ) ) = ( 𝑆 −op 𝑇 ) ) |
| 24 |
20 23
|
mpbi |
⊢ ( 𝑆 +op ( - 1 ·op 𝑇 ) ) = ( 𝑆 −op 𝑇 ) |