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)) ⊆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: ℝ
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
subtype_rel: A ⊆r 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: b supposing a
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
rneq: x ≠ y
, 
or: P ∨ Q
, 
all: ∀x:A. B[x]
, 
prop: ℙ
, 
m-interior-point: m-interior-point(X;d;A;p)
, 
exists: ∃x:A. B[x]
, 
nat_plus: ℕ+
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ 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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