Nuprl Lemma : m-ball-boundary-subtype-m-sphere

[X:Type]. ∀[d:metric(X)]. ∀[c:X]. ∀[r:ℝ].  (m-boundary(X;d;m-ball(X;d;c;r)) ⊆m-sphere(X;d;c;r))


Proof




Definitions occuring in Statement :  m-sphere: m-sphere(X;d;c;r) m-ball: m-ball(X;d;c;r) m-boundary: m-boundary(X;d;A) metric: metric(X) real: subtype_rel: A ⊆B uall: [x:A]. B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T subtype_rel: A ⊆B m-boundary: m-boundary(X;d;A) m-sphere: m-sphere(X;d;c;r) m-ball: m-ball(X;d;c;r) uimplies: supposing a not: ¬A implies:  Q rneq: x ≠ y or: P ∨ Q all: x:A. B[x] prop: m-interior-point: m-interior-point(X;d;A;p) exists: x:A. B[x] nat_plus: + guard: {T} iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q rless: x < y sq_exists: x:A [B[x]] decidable: Dec(P) satisfiable_int_formula: satisfiable_int_formula(fmla) false: False top: Top so_lambda: λ2x.t[x] so_apply: x[s] respects-equality: respects-equality(S;T) uiff: uiff(P;Q) req_int_terms: t1 ≡ t2 rev_uimplies: rev_uimplies(P;Q) rge: x ≥ y

Latex:
\mforall{}[X:Type].  \mforall{}[d:metric(X)].  \mforall{}[c:X].  \mforall{}[r:\mBbbR{}].    (m-boundary(X;d;m-ball(X;d;c;r))  \msubseteq{}r  m-sphere(X;d;c;r))



Date html generated: 2020_05_20-AM-11_47_08
Last ObjectModification: 2019_11_07-AM-10_54_08

Theory : reals


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