Nuprl Lemma : real-fun-iff-continuous

∀a,b:ℝ.  ∀f:[a, b] ⟶ℝ. (real-fun(f;a;b) ⇐⇒ real-cont(f;a;b)) supposing a ≤ b


Proof




Definitions occuring in Statement :  real-cont: real-cont(f;a;b),  real-fun: real-fun(f;a;b),  rfun: I ⟶ℝ,  rccint: [l, u],  rleq: x ≤ y,  real: ℝ,  uimplies: b supposing a,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  member: t ∈ T,  uimplies: b supposing a,  rleq: x ≤ y,  rnonneg: rnonneg(x),  uall: ∀[x:A]. B[x],  le: A ≤ B,  and: P ∧ Q,  iff: P ⇐⇒ Q,  implies: P ⇒ Q,  prop: ℙ,  rev_implies: P ⇐ Q,  real-fun: real-fun(f;a;b),  so_lambda: λ2x.t[x],  rfun: I ⟶ℝ,  subtype_rel: A ⊆r B,  so_apply: x[s],  continuous: f[x] continuous for x ∈ I,  i-approx: i-approx(I;n),  rccint: [l, u],  real-cont: real-cont(f;a;b),  exists: ∃x:A. B[x],  sq_exists: ∃x:A [B[x]],  cand: A c∧ B,  sq_stable: SqStable(P),  squash: ↓T,  rev_uimplies: rev_uimplies(P;Q),  nat_plus: ℕ+,  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  rless: x < y,  decidable: Dec(P),  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  false: False,  top: Top,  rge: x ≥ y,  uiff: uiff(P;Q),  req_int_terms: t1 ≡ t2
Lemmas referenced :  real-continuity,  le_witness_for_triv,  real-fun_wf,  continuous-rneq,  rccint_wf,  subtype_rel_self,  rfun_wf,  req_wf,  i-member_wf,  real-cont_wf,  rleq_wf,  real_wf,  nat_plus_wf,  icompact_wf,  i-approx_wf,  sq_stable__rless,  int-to-real_wf,  rleq_functionality_wrt_implies,  rabs_wf,  rsub_wf,  rdiv_wf,  rless-int,  nat_plus_properties,  decidable__lt,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformless_wf,  itermConstant_wf,  itermVar_wf,  istype-int,  int_formula_prop_and_lemma,  istype-void,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  rless_wf,  rleq_weakening_equal,  rleq_weakening,  itermSubtract_wf,  req-iff-rsub-is-0,  real_polynomial_null,  real_term_value_sub_lemma,  real_term_value_var_lemma,  real_term_value_const_lemma,  req-iff-not-rneq,  rneq_wf
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  hypothesis,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  isect_memberFormation_alt,  sqequalRule,  lambdaEquality_alt,  isectElimination,  productElimination,  equalityTransitivity,  equalitySymmetry,  independent_isectElimination,  functionIsTypeImplies,  inhabitedIsType,  rename,  independent_pairFormation,  universeIsType,  applyEquality,  independent_functionElimination,  setElimination,  setIsType,  dependent_set_memberFormation_alt,  natural_numberEquality,  imageMemberEquality,  baseClosed,  imageElimination,  dependent_set_memberEquality_alt,  because_Cache,  closedConclusion,  inrFormation_alt,  unionElimination,  approximateComputation,  dependent_pairFormation_alt,  int_eqEquality,  isect_memberEquality_alt,  voidElimination,  productIsType,  functionIsType

Latex:
\mforall{}a,b:\mBbbR{}.    \mforall{}f:[a,  b]  {}\mrightarrow{}\mBbbR{}.  (real-fun(f;a;b)  \mLeftarrow{}{}\mRightarrow{}  real-cont(f;a;b))  supposing  a  \mleq{}  b



Date html generated: 2019_10_30-AM-07_15_21
Last ObjectModification: 2019_10_09-PM-05_37_58

Theory : reals


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