Nuprl Lemma : ifun-alt

∀I:Interval. ∀[f:I ⟶ℝ]. (ifun(f;I)) supposing ((∀x,y:{x:ℝ| x ∈ 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: x = y,  real: ℝ,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  implies: P ⇒ Q,  set: {x:A| B[x]} ,  apply: f a
Definitions unfolded in proof :  guard: {T},  cand: A c∧ B,  top: Top,  subinterval: I ⊆ J ,  and: P ∧ Q,  icompact: icompact(I),  squash: ↓T,  sq_stable: SqStable(P),  so_apply: x[s],  so_lambda: λ2x.t[x],  prop: ℙ,  member: t ∈ T,  implies: P ⇒ Q,  real-fun: real-fun(f;a;b),  ifun: ifun(f;I),  uimplies: b 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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