Description: The gcd of 420 and 8 is 4. (Contributed by metakunt, 25-Apr-2024)
Ref | Expression | ||
---|---|---|---|
Assertion | 420gcd8e4 | ⊢ ( ; ; 4 2 0 gcd 8 ) = 4 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 8nn | ⊢ 8 ∈ ℕ | |
2 | 4nn | ⊢ 4 ∈ ℕ | |
3 | 5nn0 | ⊢ 5 ∈ ℕ0 | |
4 | 2nn | ⊢ 2 ∈ ℕ | |
5 | 3 4 | decnncl | ⊢ ; 5 2 ∈ ℕ |
6 | 5 | nnzi | ⊢ ; 5 2 ∈ ℤ |
7 | 1 2 6 | gcdaddmzz2nncomi | ⊢ ( 8 gcd 4 ) = ( 8 gcd ( ( ; 5 2 · 8 ) + 4 ) ) |
8 | 4nn0 | ⊢ 4 ∈ ℕ0 | |
9 | 1nn0 | ⊢ 1 ∈ ℕ0 | |
10 | 8 9 | deccl | ⊢ ; 4 1 ∈ ℕ0 |
11 | 6nn0 | ⊢ 6 ∈ ℕ0 | |
12 | 0nn0 | ⊢ 0 ∈ ℕ0 | |
13 | eqid | ⊢ ; ; 4 1 6 = ; ; 4 1 6 | |
14 | 8 | dec0h | ⊢ 4 = ; 0 4 |
15 | 1p1e2 | ⊢ ( 1 + 1 ) = 2 | |
16 | 10 | nn0cni | ⊢ ; 4 1 ∈ ℂ |
17 | 16 | addid1i | ⊢ ( ; 4 1 + 0 ) = ; 4 1 |
18 | 8 9 15 17 | decsuc | ⊢ ( ( ; 4 1 + 0 ) + 1 ) = ; 4 2 |
19 | 6p4e10 | ⊢ ( 6 + 4 ) = ; 1 0 | |
20 | 10 11 12 8 13 14 18 19 | decaddc2 | ⊢ ( ; ; 4 1 6 + 4 ) = ; ; 4 2 0 |
21 | 8nn0 | ⊢ 8 ∈ ℕ0 | |
22 | 2nn0 | ⊢ 2 ∈ ℕ0 | |
23 | eqid | ⊢ ; 5 2 = ; 5 2 | |
24 | 0p1e1 | ⊢ ( 0 + 1 ) = 1 | |
25 | 8t5e40 | ⊢ ( 8 · 5 ) = ; 4 0 | |
26 | 8 12 24 25 | decsuc | ⊢ ( ( 8 · 5 ) + 1 ) = ; 4 1 |
27 | 8t2e16 | ⊢ ( 8 · 2 ) = ; 1 6 | |
28 | 21 3 22 23 11 9 26 27 | decmul2c | ⊢ ( 8 · ; 5 2 ) = ; ; 4 1 6 |
29 | 1 5 | mulcomnni | ⊢ ( 8 · ; 5 2 ) = ( ; 5 2 · 8 ) |
30 | 28 29 | eqtr3i | ⊢ ; ; 4 1 6 = ( ; 5 2 · 8 ) |
31 | 30 | oveq1i | ⊢ ( ; ; 4 1 6 + 4 ) = ( ( ; 5 2 · 8 ) + 4 ) |
32 | 20 31 | eqtr3i | ⊢ ; ; 4 2 0 = ( ( ; 5 2 · 8 ) + 4 ) |
33 | 32 | oveq2i | ⊢ ( 8 gcd ; ; 4 2 0 ) = ( 8 gcd ( ( ; 5 2 · 8 ) + 4 ) ) |
34 | 7 33 | eqtr4i | ⊢ ( 8 gcd 4 ) = ( 8 gcd ; ; 4 2 0 ) |
35 | 1 2 | gcdcomnni | ⊢ ( 8 gcd 4 ) = ( 4 gcd 8 ) |
36 | 4t2e8 | ⊢ ( 4 · 2 ) = 8 | |
37 | 36 | oveq2i | ⊢ ( 4 gcd ( 4 · 2 ) ) = ( 4 gcd 8 ) |
38 | 2 4 | gcdmultiplei | ⊢ ( 4 gcd ( 4 · 2 ) ) = 4 |
39 | 37 38 | eqtr3i | ⊢ ( 4 gcd 8 ) = 4 |
40 | 35 39 | eqtri | ⊢ ( 8 gcd 4 ) = 4 |
41 | 8 4 | decnncl | ⊢ ; 4 2 ∈ ℕ |
42 | 41 | decnncl2 | ⊢ ; ; 4 2 0 ∈ ℕ |
43 | 1 42 | gcdcomnni | ⊢ ( 8 gcd ; ; 4 2 0 ) = ( ; ; 4 2 0 gcd 8 ) |
44 | 34 40 43 | 3eqtr3ri | ⊢ ( ; ; 4 2 0 gcd 8 ) = 4 |