Nuprl Lemma : real-fun-implies-sfun-general

∀[I:Interval]. ∀[f:I ⟶ℝ].
  ∀x,y:{x:ℝ| x ∈ I} .  (f x ≠ f y ⇒ x ≠ y) supposing ∀x,y:{x:ℝ| x ∈ I} .  ((x = y) ⇒ ((f x) = (f y)))


Proof




Definitions occuring in Statement :  rfun: I ⟶ℝ,  i-member: r ∈ I,  interval: Interval,  rneq: x ≠ y,  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 :  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  member: t ∈ T,  all: ∀x:A. B[x],  implies: P ⇒ Q,  rfun: I ⟶ℝ,  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s],  or: P ∨ Q,  not: ¬A,  guard: {T},  false: False,  iff: P ⇐⇒ Q,  and: P ∧ Q,  sq_stable: SqStable(P),  squash: ↓T,  subtype_rel: A ⊆r B,  top: Top,  cand: A c∧ B,  subinterval: I ⊆ J ,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced :  req_witness,  i-member_wf,  req_wf,  real_wf,  real-weak-Markov,  rneq_wf,  set_wf,  all_wf,  rfun_wf,  interval_wf,  rneq-cases,  not_wf,  rneq_irreflexivity,  rneq_functionality,  req_weakening,  rmin-rmax-subinterval,  sq_stable__i-member,  rmin-rleq-rmax,  rmin_wf,  rmax_wf,  equal_wf,  member_rccint_lemma,  rleq_wf,  rmin_ub,  rleq-rmax,  rmin-rleq,  rccint_wf,  rmax_lb,  req_functionality,  rmin_functionality,  rmax_functionality,  rmin-req,  rmax-req
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  cut,  introduction,  sqequalRule,  sqequalHypSubstitution,  lambdaEquality,  dependent_functionElimination,  thin,  hypothesisEquality,  extract_by_obid,  isectElimination,  applyEquality,  setElimination,  rename,  dependent_set_memberEquality,  hypothesis,  because_Cache,  independent_functionElimination,  setEquality,  lambdaFormation,  independent_isectElimination,  functionEquality,  unionElimination,  inlFormation,  inrFormation,  voidElimination,  productElimination,  imageMemberEquality,  baseClosed,  imageElimination,  equalityTransitivity,  equalitySymmetry,  isect_memberEquality,  voidEquality,  independent_pairFormation,  productEquality

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



Date html generated: 2017_10_03-AM-09_57_00
Last ObjectModification: 2017_08_31-AM-11_52_29

Theory : reals


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