Metamath Proof Explorer


Theorem lermxnn0

Description: The X-sequence is monotonic on NN0 . (Contributed by Stefan O'Rear, 4-Oct-2014)

Ref Expression
Assertion lermxnn0 ( ( 𝐴 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑀 ∈ ℕ0 ∧ 𝑁 ∈ ℕ0 ) → ( 𝑀 ≤ 𝑁 ↔ ( 𝐴 Xrm 𝑀 ) ≤ ( 𝐴 Xrm 𝑁 ) ) )

Proof

Step Hyp Ref Expression
1 oveq2 ⊢ ( 𝑎 = 𝑏 → ( 𝐴 Xrm 𝑎 ) = ( 𝐴 Xrm 𝑏 ) )
2 oveq2 ⊢ ( 𝑎 = 𝑀 → ( 𝐴 Xrm 𝑎 ) = ( 𝐴 Xrm 𝑀 ) )
3 oveq2 ⊢ ( 𝑎 = 𝑁 → ( 𝐴 Xrm 𝑎 ) = ( 𝐴 Xrm 𝑁 ) )
4 nn0ssre ⊢ ℕ0 ⊆ ℝ
5 nn0z ⊢ ( 𝑎 ∈ ℕ0 → 𝑎 ∈ ℤ )
6 frmx ⊢ Xrm : ( ( ℤ≥ ‘ 2 ) × ℤ ) ⟶ ℕ0
7 6 fovcl ⊢ ( ( 𝐴 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑎 ∈ ℤ ) → ( 𝐴 Xrm 𝑎 ) ∈ ℕ0 )
8 5 7 sylan2 ⊢ ( ( 𝐴 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑎 ∈ ℕ0 ) → ( 𝐴 Xrm 𝑎 ) ∈ ℕ0 )
9 8 nn0red ⊢ ( ( 𝐴 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑎 ∈ ℕ0 ) → ( 𝐴 Xrm 𝑎 ) ∈ ℝ )
10 ltrmxnn0 ⊢ ( ( 𝐴 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑎 ∈ ℕ0 ∧ 𝑏 ∈ ℕ0 ) → ( 𝑎 < 𝑏 ↔ ( 𝐴 Xrm 𝑎 ) < ( 𝐴 Xrm 𝑏 ) ) )
11 10 biimpd ⊢ ( ( 𝐴 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑎 ∈ ℕ0 ∧ 𝑏 ∈ ℕ0 ) → ( 𝑎 < 𝑏 → ( 𝐴 Xrm 𝑎 ) < ( 𝐴 Xrm 𝑏 ) ) )
12 11 3expb ⊢ ( ( 𝐴 ∈ ( ℤ≥ ‘ 2 ) ∧ ( 𝑎 ∈ ℕ0 ∧ 𝑏 ∈ ℕ0 ) ) → ( 𝑎 < 𝑏 → ( 𝐴 Xrm 𝑎 ) < ( 𝐴 Xrm 𝑏 ) ) )
13 1 2 3 4 9 12 leord1 ⊢ ( ( 𝐴 ∈ ( ℤ≥ ‘ 2 ) ∧ ( 𝑀 ∈ ℕ0 ∧ 𝑁 ∈ ℕ0 ) ) → ( 𝑀 ≤ 𝑁 ↔ ( 𝐴 Xrm 𝑀 ) ≤ ( 𝐴 Xrm 𝑁 ) ) )
14 13 3impb ⊢ ( ( 𝐴 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑀 ∈ ℕ0 ∧ 𝑁 ∈ ℕ0 ) → ( 𝑀 ≤ 𝑁 ↔ ( 𝐴 Xrm 𝑀 ) ≤ ( 𝐴 Xrm 𝑁 ) ) )