Nuprl Lemma : qmin-list-bounds

∀L:ℚ List
  (0 < ||L||
  ⇒ (∀x:ℚ
        ((x ≤ qmin-list(L) ⇐⇒ (∀y∈L.x ≤ y))
        ∧ (qmin-list(L) ≤ x ⇐⇒ (∃y∈L. y ≤ x))
        ∧ (x < qmin-list(L) ⇐⇒ (∀y∈L.x < y))
        ∧ (qmin-list(L) < x ⇐⇒ (∃y∈L. y < x)))))


Proof




Definitions occuring in Statement :  qmin-list: qmin-list(L),  qle: r ≤ s,  qless: r < s,  rationals: ℚ,  l_exists: (∃x∈L. P[x]),  l_all: (∀x∈L.P[x]),  length: ||as||,  list: T List,  less_than: a < b,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  implies: P ⇒ Q,  and: P ∧ Q,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  iff: P ⇐⇒ Q,  qmin: qmin(x;y),  prop: ℙ,  rev_implies: P ⇐ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  uimplies: b supposing a,  guard: {T},  ifthenelse: if b then t else f fi ,  bfalse: ff,  exists: ∃x:A. B[x],  or: P ∨ Q,  sq_type: SQType(T),  bnot: ¬bb,  assert: ↑b,  false: False,  not: ¬A,  cand: A c∧ B,  qmin-list: qmin-list(L)
Lemmas referenced :  rationals_wf,  istype-less_than,  length_wf,  list_wf,  combine-list-rel-and,  qmin_wf,  qle_wf,  q_le_wf,  eqtt_to_assert,  assert-q_le-eq,  iff_weakening_equal,  eqff_to_assert,  bool_cases_sqequal,  subtype_base_sq,  bool_wf,  bool_subtype_base,  assert-bnot,  qmin-assoc,  assert_wf,  bnot_wf,  not_wf,  istype-assert,  istype-void,  qle_complement_qorder,  qless_transitivity_1_qorder,  qle_weakening_lt_qorder,  qle_transitivity_qorder,  bool_cases,  iff_transitivity,  iff_weakening_uiff,  assert_of_bnot,  combine-list-rel-or,  uiff_transitivity2,  equal-wf-T-base,  qless_transitivity_2_qorder,  qless_wf,  qless_transitivity
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  independent_pairFormation,  universeIsType,  cut,  introduction,  extract_by_obid,  hypothesis,  sqequalHypSubstitution,  isectElimination,  thin,  natural_numberEquality,  hypothesisEquality,  dependent_functionElimination,  sqequalRule,  lambdaEquality_alt,  inhabitedIsType,  independent_functionElimination,  productElimination,  unionElimination,  equalityElimination,  because_Cache,  independent_isectElimination,  equalityTransitivity,  equalitySymmetry,  dependent_pairFormation_alt,  equalityIstype,  promote_hyp,  instantiate,  cumulativity,  voidElimination,  productIsType,  functionIsType,  baseClosed,  unionIsType,  inlFormation_alt,  inrFormation_alt

Latex:
\mforall{}L:\mBbbQ{}  List
    (0  <  ||L||
    {}\mRightarrow{}  (\mforall{}x:\mBbbQ{}
                ((x  \mleq{}  qmin-list(L)  \mLeftarrow{}{}\mRightarrow{}  (\mforall{}y\mmember{}L.x  \mleq{}  y))
                \mwedge{}  (qmin-list(L)  \mleq{}  x  \mLeftarrow{}{}\mRightarrow{}  (\mexists{}y\mmember{}L.  y  \mleq{}  x))
                \mwedge{}  (x  <  qmin-list(L)  \mLeftarrow{}{}\mRightarrow{}  (\mforall{}y\mmember{}L.x  <  y))
                \mwedge{}  (qmin-list(L)  <  x  \mLeftarrow{}{}\mRightarrow{}  (\mexists{}y\mmember{}L.  y  <  x)))))



Date html generated: 2020_05_20-AM-09_16_05
Last ObjectModification: 2020_01_06-PM-05_24_48

Theory : rationals


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