Nuprl Lemma : interval-retraction-req

[u,v:ℝ]. ∀[x:{x:ℝx ∈ [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: y real: 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: supposing a interval-retraction: interval-retraction(u;v;r) so_lambda: λ2x.t[x] prop: so_apply: x[s] subtype_rel: A ⊆B real: cand: c∧ B sq_stable: SqStable(P) implies:  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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