Nuprl Lemma : homeo-image-boundary
∀[X,Y:Type]. ∀[dX:metric(X)]. ∀[dY:metric(Y)].
  ∀h:homeomorphic(X;dX;Y;dY)
    ∀[A:Type]
      homeo-image(m-boundary(X;dX;A);Y;dY;h) ≡ m-boundary(Y;dY;homeo-image(A;Y;dY;h)) supposing metric-subspace(X;dX;A) 
    supposing PtwiseCONT(fst(h):X ⟶ Y) ∧ PtwiseCONT(snd(h):Y ⟶ X)
Proof
Definitions occuring in Statement : 
homeo-image: homeo-image(A;Y;dY;h)
, 
m-ptwise-cont: PtwiseCONT(f:X ⟶ Y)
, 
m-boundary: m-boundary(X;d;A)
, 
metric-subspace: metric-subspace(X;d;A)
, 
homeomorphic: homeomorphic(X;dX;Y;dY)
, 
metric: metric(X)
, 
ext-eq: A ≡ B
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
pi1: fst(t)
, 
pi2: snd(t)
, 
all: ∀x:A. B[x]
, 
and: P ∧ Q
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
uimplies: b supposing a
, 
and: P ∧ Q
, 
metric-subspace: metric-subspace(X;d;A)
, 
uiff: uiff(P;Q)
, 
homeomorphic: homeomorphic(X;dX;Y;dY)
, 
exists: ∃x:A. B[x]
, 
sq_exists: ∃x:A [B[x]]
, 
ext-eq: A ≡ B
, 
subtype_rel: A ⊆r B
, 
homeo-image: homeo-image(A;Y;dY;h)
, 
pi1: fst(t)
, 
m-boundary: m-boundary(X;d;A)
, 
mfun: FUN(X ⟶ Y)
, 
prop: ℙ
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
false: False
, 
guard: {T}
, 
pi2: snd(t)
, 
top: Top
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
decidable: Dec(P)
, 
rev_implies: P 
⇐ Q
, 
iff: P 
⇐⇒ Q
, 
or: P ∨ Q
, 
rneq: x ≠ y
, 
nat_plus: ℕ+
, 
m-interior-point: m-interior-point(X;d;A;p)
, 
respects-equality: respects-equality(S;T)
, 
rev_uimplies: rev_uimplies(P;Q)
, 
m-ptwise-cont: PtwiseCONT(f:X ⟶ Y)
, 
rless: x < y
, 
squash: ↓T
, 
is-mfun: f:FUN(X;Y)
, 
rge: x ≥ y
, 
rgt: x > y
Latex:
\mforall{}[X,Y:Type].  \mforall{}[dX:metric(X)].  \mforall{}[dY:metric(Y)].
    \mforall{}h:homeomorphic(X;dX;Y;dY)
        \mforall{}[A:Type]
            homeo-image(m-boundary(X;dX;A);Y;dY;h)  \mequiv{}  m-boundary(Y;dY;homeo-image(A;Y;dY;h)) 
            supposing  metric-subspace(X;dX;A) 
        supposing  PtwiseCONT(fst(h):X  {}\mrightarrow{}  Y)  \mwedge{}  PtwiseCONT(snd(h):Y  {}\mrightarrow{}  X)
Date html generated:
2020_05_20-AM-11_52_37
Last ObjectModification:
2020_01_06-PM-00_16_47
Theory : reals
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