Nuprl Lemma : ifun-alt

I:Interval. ∀[f:I ⟶ℝ]. (ifun(f;I)) supposing ((∀x,y:{x:ℝx ∈ I} .  ((x y)  ((f x) (f y)))) and icompact(I))


Proof




Definitions occuring in Statement :  ifun: ifun(f;I) icompact: icompact(I) rfun: I ⟶ℝ i-member: r ∈ I interval: Interval req: y real: uimplies: supposing a uall: [x:A]. B[x] all: x:A. B[x] implies:  Q set: {x:A| B[x]}  apply: a
Definitions unfolded in proof :  guard: {T} cand: c∧ B top: Top subinterval: I ⊆  and: P ∧ Q icompact: icompact(I) squash: T sq_stable: SqStable(P) so_apply: x[s] so_lambda: λ2x.t[x] prop: member: t ∈ T implies:  Q real-fun: real-fun(f;a;b) ifun: ifun(f;I) uimplies: supposing a uall: [x:A]. B[x] all: x:A. B[x] r-ap: f(x)
Lemmas referenced :  sq_stable__req sq_stable__rleq member_rccint_lemma trivial-subinterval sq_stable__icompact interval_wf rfun_wf icompact_wf sq_stable__i-member r-ap_wf all_wf right-endpoint_wf left-endpoint_wf rccint_wf i-member_wf real_wf set_wf req_wf
Rules used in proof :  dependent_set_memberEquality independent_pairFormation voidEquality voidElimination isect_memberEquality productElimination imageElimination baseClosed imageMemberEquality independent_functionElimination dependent_functionElimination functionEquality setEquality independent_isectElimination lambdaEquality because_Cache hypothesis hypothesisEquality rename setElimination thin isectElimination sqequalHypSubstitution extract_by_obid introduction cut isect_memberFormation lambdaFormation computationStep sqequalTransitivity sqequalReflexivity sqequalRule sqequalSubstitution

Latex:
\mforall{}I:Interval
    \mforall{}[f:I  {}\mrightarrow{}\mBbbR{}]
        (ifun(f;I))  supposing  ((\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  I\}  .    ((x  =  y)  {}\mRightarrow{}  ((f  x)  =  (f  y))))  and  icompact(I))



Date html generated: 2018_07_29-AM-09_40_30
Last ObjectModification: 2018_07_02-PM-00_31_17

Theory : reals


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