Nuprl Lemma : qmin-list-bounds

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


Proof




Definitions occuring in Statement :  qmin-list: qmin-list(L) qle: r ≤ s qless: r < s rationals: l_exists: (∃x∈L. P[x]) l_all: (∀x∈L.P[x]) length: ||as|| list: List less_than: a < b all: x:A. B[x] iff: ⇐⇒ Q implies:  Q and: P ∧ Q natural_number: $n
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q and: P ∧ Q member: t ∈ T uall: [x:A]. B[x] so_lambda: λ2y.t[x; y] so_apply: x[s1;s2] iff: ⇐⇒ Q qmin: qmin(x;y) prop: rev_implies:  Q bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) uimplies: supposing a guard: {T} ifthenelse: if then else fi  bfalse: ff exists: x:A. B[x] or: P ∨ Q sq_type: SQType(T) bnot: ¬bb assert: b false: False not: ¬A cand: 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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