Metamath Proof Explorer


Definition df-lcmf

Description: Define the _lcm function on a set of integers. (Contributed by AV, 21-Aug-2020) (Revised by AV, 16-Sep-2020)

Ref Expression
Assertion df-lcmf lcm = ( 𝑧 ∈ 𝒫 ℤ ↦ if ( 0 ∈ 𝑧 , 0 , inf ( { 𝑛 ∈ ℕ ∣ ∀ 𝑚𝑧 𝑚𝑛 } , ℝ , < ) ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 clcmf lcm
1 vz 𝑧
2 cz
3 2 cpw 𝒫 ℤ
4 cc0 0
5 1 cv 𝑧
6 4 5 wcel 0 ∈ 𝑧
7 vn 𝑛
8 cn
9 vm 𝑚
10 9 cv 𝑚
11 cdvds
12 7 cv 𝑛
13 10 12 11 wbr 𝑚𝑛
14 13 9 5 wral 𝑚𝑧 𝑚𝑛
15 14 7 8 crab { 𝑛 ∈ ℕ ∣ ∀ 𝑚𝑧 𝑚𝑛 }
16 cr
17 clt <
18 15 16 17 cinf inf ( { 𝑛 ∈ ℕ ∣ ∀ 𝑚𝑧 𝑚𝑛 } , ℝ , < )
19 6 4 18 cif if ( 0 ∈ 𝑧 , 0 , inf ( { 𝑛 ∈ ℕ ∣ ∀ 𝑚𝑧 𝑚𝑛 } , ℝ , < ) )
20 1 3 19 cmpt ( 𝑧 ∈ 𝒫 ℤ ↦ if ( 0 ∈ 𝑧 , 0 , inf ( { 𝑛 ∈ ℕ ∣ ∀ 𝑚𝑧 𝑚𝑛 } , ℝ , < ) ) )
21 0 20 wceq lcm = ( 𝑧 ∈ 𝒫 ℤ ↦ if ( 0 ∈ 𝑧 , 0 , inf ( { 𝑛 ∈ ℕ ∣ ∀ 𝑚𝑧 𝑚𝑛 } , ℝ , < ) ) )