Nuprl Lemma : real-vec-norm-eq-iff

[n:ℕ]. ∀[x:ℝ^n]. ∀[r:ℝ].  uiff(||x|| r;(x⋅r^2) ∧ (r0 ≤ r))


Proof




Definitions occuring in Statement :  real-vec-norm: ||x|| dot-product: x⋅y real-vec: ^n rleq: x ≤ y rnexp: x^k1 req: y int-to-real: r(n) real: nat: uiff: uiff(P;Q) uall: [x:A]. B[x] and: P ∧ Q natural_number: $n
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a nat: le: A ≤ B less_than': less_than'(a;b) not: ¬A implies:  Q false: False rleq: x ≤ y rnonneg: rnonneg(x) all: x:A. B[x] prop: guard: {T} rev_uimplies: rev_uimplies(P;Q) real-vec-norm: ||x|| subtype_rel: A ⊆B

Latex:
\mforall{}[n:\mBbbN{}].  \mforall{}[x:\mBbbR{}\^{}n].  \mforall{}[r:\mBbbR{}].    uiff(||x||  =  r;(x\mcdot{}x  =  r\^{}2)  \mwedge{}  (r0  \mleq{}  r))



Date html generated: 2020_05_20-PM-00_36_16
Last ObjectModification: 2019_12_14-PM-03_05_00

Theory : reals


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