Nuprl Lemma : stable-union-metric-subspace

∀[X:Type]. ∀[d:metric(X)]. ∀[T:Type]. ∀[P:T ⟶ X ⟶ ℙ].
  metric-subspace(X;d;stable-union(X;T;i,x.P[i;x])) supposing ∀i:T. ∀x,y:X.  (P[i;x] ⇒ y ≡ x ⇒ P[i;y])


Proof




Definitions occuring in Statement :  metric-subspace: metric-subspace(X;d;A),  meq: x ≡ y,  metric: metric(X),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  prop: ℙ,  so_apply: x[s1;s2],  all: ∀x:A. B[x],  implies: P ⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  guard: {T},  false: False,  not: ¬A,  subtype_rel: A ⊆r B,  so_lambda: λ2x y.t[x; y],  implies: P ⇒ Q,  all: ∀x:A. B[x],  so_apply: x[s],  so_apply: x[s1;s2],  exists: ∃x:A. B[x],  prop: ℙ,  so_lambda: λ2x.t[x],  stable-union: Error :stable-union,  and: P ∧ Q,  metric-subspace: metric-subspace(X;d;A),  uimplies: b supposing a,  member: t ∈ T,  uall: ∀[x:A]. B[x]
Lemmas referenced :  istype-void,  istype-universe,  metric_wf,  subtype_rel_self,  strong-subtype_witness,  Error :stable-union_wf,  meq_wf,  strong-subtype-self,  not_wf,  strong-subtype-set3
Rules used in proof :  voidElimination,  productIsType,  dependent_pairFormation_alt,  promote_hyp,  dependent_set_memberEquality_alt,  isectIsTypeImplies,  isect_memberEquality_alt,  universeEquality,  instantiate,  functionIsType,  functionIsTypeImplies,  equalitySymmetry,  equalityTransitivity,  axiomEquality,  dependent_functionElimination,  independent_functionElimination,  independent_pairEquality,  productElimination,  inhabitedIsType,  rename,  setElimination,  lambdaFormation_alt,  independent_isectElimination,  universeIsType,  hypothesis,  applyEquality,  productEquality,  lambdaEquality_alt,  sqequalRule,  because_Cache,  hypothesisEquality,  thin,  isectElimination,  sqequalHypSubstitution,  extract_by_obid,  independent_pairFormation,  cut,  introduction,  isect_memberFormation_alt,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution

Latex:
\mforall{}[X:Type].  \mforall{}[d:metric(X)].  \mforall{}[T:Type].  \mforall{}[P:T  {}\mrightarrow{}  X  {}\mrightarrow{}  \mBbbP{}].
    metric-subspace(X;d;stable-union(X;T;i,x.P[i;x])) 
    supposing  \mforall{}i:T.  \mforall{}x,y:X.    (P[i;x]  {}\mRightarrow{}  y  \mequiv{}  x  {}\mRightarrow{}  P[i;y])



Date html generated: 2019_10_30-AM-06_31_28
Last ObjectModification: 2019_10_24-AM-10_23_16

Theory : reals


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