Nuprl Lemma : mfun-strong-subtype

∀[X,Y:Type]. ∀[d:metric(X)]. ∀[d':metric(Y)]. ∀[A:Type].
  strong-subtype(FUN(X ⟶ A);FUN(X ⟶ Y)) supposing metric-subspace(Y;d';A)


Proof




Definitions occuring in Statement :  metric-subspace: metric-subspace(X;d;A),  mfun: FUN(X ⟶ Y),  metric: metric(X),  strong-subtype: strong-subtype(A;B),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  strong-subtype: strong-subtype(A;B),  member: t ∈ T,  metric-subspace: metric-subspace(X;d;A),  and: P ∧ Q,  subtype_rel: A ⊆r B,  cand: A c∧ B,  sq_stable: SqStable(P),  implies: P ⇒ Q,  squash: ↓T,  exists: ∃x:A. B[x],  prop: ℙ,  mfun: FUN(X ⟶ Y),  is-mfun: f:FUN(X;Y),  all: ∀x:A. B[x],  guard: {T}
Lemmas referenced :  sq_stable__subtype_rel,  mfun_wf,  metric-on-subtype,  mfun-subtype,  equal_wf,  is-mfun_wf,  metric-subspace_wf,  metric_wf,  istype-universe,  meq_weakening
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  productElimination,  applyEquality,  independent_isectElimination,  hypothesis,  sqequalRule,  independent_functionElimination,  imageMemberEquality,  baseClosed,  imageElimination,  independent_pairFormation,  setEquality,  productEquality,  lambdaEquality_alt,  setElimination,  rename,  applyLambdaEquality,  dependent_set_memberEquality_alt,  universeIsType,  because_Cache,  setIsType,  productIsType,  equalityIstype,  inhabitedIsType,  instantiate,  universeEquality,  functionExtensionality,  dependent_functionElimination,  equalitySymmetry,  equalityTransitivity,  lambdaFormation_alt

Latex:
\mforall{}[X,Y:Type].  \mforall{}[d:metric(X)].  \mforall{}[d':metric(Y)].  \mforall{}[A:Type].
    strong-subtype(FUN(X  {}\mrightarrow{}  A);FUN(X  {}\mrightarrow{}  Y))  supposing  metric-subspace(Y;d';A)



Date html generated: 2019_10_30-AM-06_32_28
Last ObjectModification: 2019_10_02-AM-10_06_18

Theory : reals


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