Nuprl Lemma : inf-as-sup

∀[A:Set(ℝ)]. ∀b:ℝ. (inf(A) = b ⇐⇒ sup(-(A)) = -(b))


Proof




Definitions occuring in Statement :  rset-neg: -(A),  inf: inf(A) = b,  sup: sup(A) = b,  rset: Set(ℝ),  rminus: -(x),  real: ℝ,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q
Definitions unfolded in proof :  sup: sup(A) = b,  inf: inf(A) = b,  all: ∀x:A. B[x],  member: t ∈ T,  top: Top,  upper-bound: A ≤ b,  lower-bound: lower-bound(A;b),  uall: ∀[x:A]. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  uimplies: b supposing a,  rev_implies: P ⇐ Q,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  true: True,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  rleq: x ≤ y,  rnonneg: rnonneg(x),  le: A ≤ B,  prop: ℙ,  exists: ∃x:A. B[x],  subtype_rel: A ⊆r B,  guard: {T},  rsub: x - y,  req_int_terms: t1 ≡ t2,  false: False,  not: ¬A
Lemmas referenced :  member_rset_neg_lemma,  istype-void,  rmul_reverses_rleq_iff,  int-to-real_wf,  rminus_wf,  rless-int,  le_witness_for_triv,  rset-member_wf,  squash_wf,  true_wf,  rminus-rminus-eq,  subtype_rel_self,  iff_weakening_equal,  rmul_reverses_rless_iff,  rsub_wf,  rless_wf,  rleq_wf,  radd_wf,  real_wf,  rset_wf,  rmul_wf,  itermSubtract_wf,  itermMultiply_wf,  itermMinus_wf,  itermVar_wf,  itermConstant_wf,  itermAdd_wf,  rleq_functionality,  req-iff-rsub-is-0,  real_polynomial_null,  istype-int,  real_term_value_sub_lemma,  real_term_value_mul_lemma,  real_term_value_minus_lemma,  real_term_value_var_lemma,  real_term_value_const_lemma,  rless_functionality,  real_term_value_add_lemma
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  isect_memberEquality_alt,  voidElimination,  hypothesis,  isect_memberFormation_alt,  lambdaFormation_alt,  independent_pairFormation,  productElimination,  isectElimination,  hypothesisEquality,  minusEquality,  natural_numberEquality,  independent_isectElimination,  independent_functionElimination,  imageMemberEquality,  baseClosed,  lambdaEquality_alt,  equalityTransitivity,  equalitySymmetry,  functionIsTypeImplies,  inhabitedIsType,  universeIsType,  dependent_pairFormation_alt,  promote_hyp,  applyEquality,  imageElimination,  because_Cache,  instantiate,  universeEquality,  productIsType,  functionIsType,  approximateComputation,  int_eqEquality

Latex:
\mforall{}[A:Set(\mBbbR{})].  \mforall{}b:\mBbbR{}.  (inf(A)  =  b  \mLeftarrow{}{}\mRightarrow{}  sup(-(A))  =  -(b))



Date html generated: 2019_10_29-AM-10_44_27
Last ObjectModification: 2019_04_19-PM-06_09_11

Theory : reals


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