Nuprl Lemma : inf-rleq

∀[A:Set(ℝ)]. ∀b,c:ℝ.  (inf(A) = b ⇒ (b ≤ c ⇐⇒ ∀e:ℝ. ((r0 < e) ⇒ (∃x:ℝ. ((x ∈ A) ∧ ((x - e) ≤ c))))))


Proof




Definitions occuring in Statement :  inf: inf(A) = b,  rset-member: x ∈ A,  rset: Set(ℝ),  rleq: x ≤ y,  rless: x < y,  rsub: x - y,  int-to-real: r(n),  real: ℝ,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  implies: P ⇒ Q,  and: P ∧ Q,  natural_number: $n
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  implies: P ⇒ Q,  iff: P ⇐⇒ Q,  and: P ∧ Q,  inf: inf(A) = b,  member: t ∈ T,  prop: ℙ,  rev_implies: P ⇐ Q,  rleq: x ≤ y,  rnonneg: rnonneg(x),  le: A ≤ B,  uimplies: b supposing a,  exists: ∃x:A. B[x],  cand: A c∧ B,  uiff: uiff(P;Q),  req_int_terms: t1 ≡ t2,  false: False,  not: ¬A,  top: Top,  guard: {T},  rev_uimplies: rev_uimplies(P;Q),  sq_stable: SqStable(P),  squash: ↓T,  lower-bound: lower-bound(A;b),  rge: x ≥ y
Lemmas referenced :  rless_wf,  int-to-real_wf,  rleq_wf,  le_witness_for_triv,  rset-member_wf,  rsub_wf,  inf_wf,  real_wf,  rset_wf,  radd-preserves-rless,  radd_wf,  rminus_wf,  itermSubtract_wf,  itermAdd_wf,  itermMinus_wf,  itermVar_wf,  rless_functionality,  req_weakening,  req-iff-rsub-is-0,  real_polynomial_null,  istype-int,  real_term_value_sub_lemma,  istype-void,  real_term_value_add_lemma,  real_term_value_minus_lemma,  real_term_value_var_lemma,  real_term_value_const_lemma,  rless_transitivity1,  rleq_weakening_rless,  rleq_functionality,  rleq-iff-all-rless,  sq_stable__rleq,  rleq-implies-rleq,  rleq_functionality_wrt_implies,  rleq_weakening_equal
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  lambdaFormation_alt,  independent_pairFormation,  sqequalHypSubstitution,  productElimination,  thin,  universeIsType,  cut,  introduction,  extract_by_obid,  isectElimination,  natural_numberEquality,  hypothesis,  hypothesisEquality,  inhabitedIsType,  sqequalRule,  lambdaEquality_alt,  dependent_functionElimination,  equalityTransitivity,  equalitySymmetry,  independent_isectElimination,  functionIsTypeImplies,  functionIsType,  productIsType,  because_Cache,  independent_functionElimination,  dependent_pairFormation_alt,  approximateComputation,  int_eqEquality,  isect_memberEquality_alt,  voidElimination,  setIsType,  setElimination,  rename,  imageMemberEquality,  baseClosed,  imageElimination

Latex:
\mforall{}[A:Set(\mBbbR{})]
    \mforall{}b,c:\mBbbR{}.    (inf(A)  =  b  {}\mRightarrow{}  (b  \mleq{}  c  \mLeftarrow{}{}\mRightarrow{}  \mforall{}e:\mBbbR{}.  ((r0  <  e)  {}\mRightarrow{}  (\mexists{}x:\mBbbR{}.  ((x  \mmember{}  A)  \mwedge{}  ((x  -  e)  \mleq{}  c))))))



Date html generated: 2019_10_29-AM-10_40_17
Last ObjectModification: 2019_04_19-PM-03_59_11

Theory : reals


Home Index