Nuprl Lemma : metric-strong-extensionality

∀[X:Type]
  ∀d:metric(X)
    (mcomplete(X with d)
    ⇒ (∀Y:Type. ∀d':metric(Y). ∀f:X ⟶ Y.
          ((∀x1,x2:X.  (x1 ≡ x2 ⇒ f[x1] ≡ f[x2])) ⇒ (∀x1,x2:X.  (f[x1] # f[x2] ⇒ x1 # x2)))))


Proof




Definitions occuring in Statement :  mcomplete: mcomplete(M),  mk-metric-space: X with d,  msep: x # y,  meq: x ≡ y,  metric: metric(X),  uall: ∀[x:A]. B[x],  so_apply: x[s],  all: ∀x:A. B[x],  implies: P ⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  all: ∀x:A. B[x],  implies: P ⇒ Q,  so_apply: x[s],  prop: ℙ,  or: P ∨ Q,  not: ¬A,  false: False,  msep: x # y,  meq: x ≡ y,  mdist: mdist(d;x;y),  guard: {T},  uimplies: b supposing a,  uiff: uiff(P;Q),  and: P ∧ Q
Lemmas referenced :  metric-weak-Markov,  msep_wf,  meq_wf,  metric_wf,  mcomplete_wf,  mk-metric-space_wf,  istype-universe,  msep-or,  istype-void,  rless_transitivity1,  int-to-real_wf,  mdist_wf,  rleq_weakening,  rless_irreflexivity,  req_functionality,  mdist-symm,  req_weakening
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  hypothesis,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  lambdaFormation_alt,  dependent_functionElimination,  independent_functionElimination,  because_Cache,  universeIsType,  applyEquality,  inhabitedIsType,  sqequalRule,  functionIsType,  instantiate,  universeEquality,  unionElimination,  inlFormation_alt,  inrFormation_alt,  natural_numberEquality,  independent_isectElimination,  voidElimination,  productElimination

Latex:
\mforall{}[X:Type]
    \mforall{}d:metric(X)
        (mcomplete(X  with  d)
        {}\mRightarrow{}  (\mforall{}Y:Type.  \mforall{}d':metric(Y).  \mforall{}f:X  {}\mrightarrow{}  Y.
                    ((\mforall{}x1,x2:X.    (x1  \mequiv{}  x2  {}\mRightarrow{}  f[x1]  \mequiv{}  f[x2]))  {}\mRightarrow{}  (\mforall{}x1,x2:X.    (f[x1]  \#  f[x2]  {}\mRightarrow{}  x1  \#  x2)))))



Date html generated: 2019_10_30-AM-06_47_36
Last ObjectModification: 2019_10_02-AM-10_58_39

Theory : reals


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