Description: Lemma for axsegcon . Show that the distance between two points is nonnegative. (Contributed by Scott Fenton, 17-Sep-2013)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | axsegconlem2.1 | ⊢ 𝑆 = Σ 𝑝 ∈ ( 1 ... 𝑁 ) ( ( ( 𝐴 ‘ 𝑝 ) − ( 𝐵 ‘ 𝑝 ) ) ↑ 2 ) | |
| Assertion | axsegconlem5 | ⊢ ( ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ) → 0 ≤ ( √ ‘ 𝑆 ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | axsegconlem2.1 | ⊢ 𝑆 = Σ 𝑝 ∈ ( 1 ... 𝑁 ) ( ( ( 𝐴 ‘ 𝑝 ) − ( 𝐵 ‘ 𝑝 ) ) ↑ 2 ) | |
| 2 | 1 | axsegconlem2 | ⊢ ( ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ) → 𝑆 ∈ ℝ ) | 
| 3 | 1 | axsegconlem3 | ⊢ ( ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ) → 0 ≤ 𝑆 ) | 
| 4 | 2 3 | sqrtge0d | ⊢ ( ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ) → 0 ≤ ( √ ‘ 𝑆 ) ) |