Metamath Proof Explorer
Description: Transitive law of ordering for integers. (Contributed by Alexander van
der Vekens, 3-Apr-2018)
|
|
Ref |
Expression |
|
Assertion |
zletr |
⊢ ( ( 𝐽 ∈ ℤ ∧ 𝐾 ∈ ℤ ∧ 𝐿 ∈ ℤ ) → ( ( 𝐽 ≤ 𝐾 ∧ 𝐾 ≤ 𝐿 ) → 𝐽 ≤ 𝐿 ) ) |
Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
zre |
⊢ ( 𝐽 ∈ ℤ → 𝐽 ∈ ℝ ) |
2 |
|
zre |
⊢ ( 𝐾 ∈ ℤ → 𝐾 ∈ ℝ ) |
3 |
|
zre |
⊢ ( 𝐿 ∈ ℤ → 𝐿 ∈ ℝ ) |
4 |
|
letr |
⊢ ( ( 𝐽 ∈ ℝ ∧ 𝐾 ∈ ℝ ∧ 𝐿 ∈ ℝ ) → ( ( 𝐽 ≤ 𝐾 ∧ 𝐾 ≤ 𝐿 ) → 𝐽 ≤ 𝐿 ) ) |
5 |
1 2 3 4
|
syl3an |
⊢ ( ( 𝐽 ∈ ℤ ∧ 𝐾 ∈ ℤ ∧ 𝐿 ∈ ℤ ) → ( ( 𝐽 ≤ 𝐾 ∧ 𝐾 ≤ 𝐿 ) → 𝐽 ≤ 𝐿 ) ) |