Step |
Hyp |
Ref |
Expression |
1 |
|
2p1e3 |
⊢ ( 2 + 1 ) = 3 |
2 |
|
0z |
⊢ 0 ∈ ℤ |
3 |
|
3z |
⊢ 3 ∈ ℤ |
4 |
|
0re |
⊢ 0 ∈ ℝ |
5 |
|
3re |
⊢ 3 ∈ ℝ |
6 |
|
3pos |
⊢ 0 < 3 |
7 |
4 5 6
|
ltleii |
⊢ 0 ≤ 3 |
8 |
|
eluz2 |
⊢ ( 3 ∈ ( ℤ≥ ‘ 0 ) ↔ ( 0 ∈ ℤ ∧ 3 ∈ ℤ ∧ 0 ≤ 3 ) ) |
9 |
2 3 7 8
|
mpbir3an |
⊢ 3 ∈ ( ℤ≥ ‘ 0 ) |
10 |
1 9
|
eqeltri |
⊢ ( 2 + 1 ) ∈ ( ℤ≥ ‘ 0 ) |
11 |
|
2z |
⊢ 2 ∈ ℤ |
12 |
|
4z |
⊢ 4 ∈ ℤ |
13 |
|
2re |
⊢ 2 ∈ ℝ |
14 |
|
4re |
⊢ 4 ∈ ℝ |
15 |
|
2lt4 |
⊢ 2 < 4 |
16 |
13 14 15
|
ltleii |
⊢ 2 ≤ 4 |
17 |
|
eluz2 |
⊢ ( 4 ∈ ( ℤ≥ ‘ 2 ) ↔ ( 2 ∈ ℤ ∧ 4 ∈ ℤ ∧ 2 ≤ 4 ) ) |
18 |
11 12 16 17
|
mpbir3an |
⊢ 4 ∈ ( ℤ≥ ‘ 2 ) |
19 |
|
fzsplit2 |
⊢ ( ( ( 2 + 1 ) ∈ ( ℤ≥ ‘ 0 ) ∧ 4 ∈ ( ℤ≥ ‘ 2 ) ) → ( 0 ... 4 ) = ( ( 0 ... 2 ) ∪ ( ( 2 + 1 ) ... 4 ) ) ) |
20 |
10 18 19
|
mp2an |
⊢ ( 0 ... 4 ) = ( ( 0 ... 2 ) ∪ ( ( 2 + 1 ) ... 4 ) ) |
21 |
|
fz0tp |
⊢ ( 0 ... 2 ) = { 0 , 1 , 2 } |
22 |
1
|
oveq1i |
⊢ ( ( 2 + 1 ) ... 4 ) = ( 3 ... 4 ) |
23 |
|
df-4 |
⊢ 4 = ( 3 + 1 ) |
24 |
23
|
oveq2i |
⊢ ( 3 ... 4 ) = ( 3 ... ( 3 + 1 ) ) |
25 |
|
fzpr |
⊢ ( 3 ∈ ℤ → ( 3 ... ( 3 + 1 ) ) = { 3 , ( 3 + 1 ) } ) |
26 |
3 25
|
ax-mp |
⊢ ( 3 ... ( 3 + 1 ) ) = { 3 , ( 3 + 1 ) } |
27 |
|
3p1e4 |
⊢ ( 3 + 1 ) = 4 |
28 |
27
|
preq2i |
⊢ { 3 , ( 3 + 1 ) } = { 3 , 4 } |
29 |
24 26 28
|
3eqtri |
⊢ ( 3 ... 4 ) = { 3 , 4 } |
30 |
22 29
|
eqtri |
⊢ ( ( 2 + 1 ) ... 4 ) = { 3 , 4 } |
31 |
21 30
|
uneq12i |
⊢ ( ( 0 ... 2 ) ∪ ( ( 2 + 1 ) ... 4 ) ) = ( { 0 , 1 , 2 } ∪ { 3 , 4 } ) |
32 |
20 31
|
eqtri |
⊢ ( 0 ... 4 ) = ( { 0 , 1 , 2 } ∪ { 3 , 4 } ) |