Nuprl Lemma : set-metric-subspace

∀[X:Type]. ∀[d:metric(X)]. ∀[P:X ⟶ ℙ].  metric-subspace(X;d;{x:X| P[x]} ) supposing ∀x,y:X.  (P[x] ⇒ y ≡ x ⇒ P[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[s],  all: ∀x:A. B[x],  implies: P ⇒ Q,  set: {x:A| B[x]} ,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  metric-subspace: metric-subspace(X;d;A),  and: P ∧ Q,  so_lambda: λ2x.t[x],  so_apply: x[s],  all: ∀x:A. B[x],  implies: P ⇒ Q,  subtype_rel: A ⊆r B,  prop: ℙ,  guard: {T}
Lemmas referenced :  strong-subtype-set2,  meq_wf,  strong-subtype_witness,  subtype_rel_self,  metric_wf,  istype-universe
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  independent_pairFormation,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  sqequalRule,  lambdaEquality_alt,  applyEquality,  universeIsType,  hypothesis,  lambdaFormation_alt,  setElimination,  rename,  dependent_set_memberEquality_alt,  because_Cache,  setIsType,  productElimination,  independent_pairEquality,  setEquality,  instantiate,  universeEquality,  independent_functionElimination,  dependent_functionElimination,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  functionIsTypeImplies,  inhabitedIsType,  functionIsType,  isect_memberEquality_alt,  isectIsTypeImplies

Latex:
\mforall{}[X:Type].  \mforall{}[d:metric(X)].  \mforall{}[P:X  {}\mrightarrow{}  \mBbbP{}].    metric-subspace(X;d;\{x:X|  P[x]\}  )  supposing  \mforall{}x,y:X.    (P[x]  \000C{}\mRightarrow{}  y  \mequiv{}  x  {}\mRightarrow{}  P[y])



Date html generated: 2019_10_30-AM-06_31_08
Last ObjectModification: 2019_10_02-AM-10_06_00

Theory : reals


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