Nuprl Lemma : interval-retraction-req

∀[u,v:ℝ]. ∀[x:{x:ℝ| x ∈ [u, v]} ].  (interval-retraction(u;v;x) = x)


Proof




Definitions occuring in Statement :  interval-retraction: interval-retraction(u;v;r),  rccint: [l, u],  i-member: r ∈ I,  req: x = y,  real: ℝ,  uall: ∀[x:A]. B[x],  set: {x:A| B[x]} 
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  member: t ∈ T,  top: Top,  and: P ∧ Q,  guard: {T},  uimplies: b supposing a,  interval-retraction: interval-retraction(u;v;r),  so_lambda: λ2x.t[x],  prop: ℙ,  so_apply: x[s],  subtype_rel: A ⊆r B,  real: ℝ,  cand: A c∧ B,  sq_stable: SqStable(P),  implies: P ⇒ Q,  squash: ↓T,  rleq: x ≤ y,  rnonneg: rnonneg(x),  le: A ≤ B,  not: ¬A,  false: False,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced :  member_rccint_lemma,  rleq_transitivity,  set_wf,  real_wf,  i-member_wf,  rccint_wf,  rleq_wf,  less_than'_wf,  rsub_wf,  nat_plus_wf,  squash_wf,  sq_stable__rleq,  sq_stable__and,  rmax-req,  rmin-req,  req_wf,  rmin_wf,  rmax_wf,  req_weakening,  uiff_transitivity,  req_functionality,  rmin_functionality
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  isect_memberEquality,  voidElimination,  voidEquality,  hypothesis,  productElimination,  isectElimination,  because_Cache,  hypothesisEquality,  independent_isectElimination,  sqequalRule,  lambdaEquality,  setElimination,  rename,  applyEquality,  minusEquality,  natural_numberEquality,  independent_functionElimination,  imageMemberEquality,  baseClosed,  imageElimination,  independent_pairFormation,  lambdaFormation,  independent_pairEquality,  axiomEquality,  equalityTransitivity,  equalitySymmetry

Latex:
\mforall{}[u,v:\mBbbR{}].  \mforall{}[x:\{x:\mBbbR{}|  x  \mmember{}  [u,  v]\}  ].    (interval-retraction(u;v;x)  =  x)



Date html generated: 2017_10_03-AM-10_05_39
Last ObjectModification: 2017_07_10-PM-05_04_39

Theory : reals


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