Nuprl Lemma : rmin_strict_lb

x,y,z:ℝ.  ((x < z) ∨ (y < z) ⇐⇒ rmin(x;y) < z)


Proof




Definitions occuring in Statement :  rless: x < y rmin: rmin(x;y) real: all: x:A. B[x] iff: ⇐⇒ Q or: P ∨ Q
Definitions unfolded in proof :  all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q implies:  Q or: P ∨ Q rless: x < y sq_exists: x:{A| B[x]} member: t ∈ T rmin: rmin(x;y) uall: [x:A]. B[x] subtype_rel: A ⊆B real: prop: rev_implies:  Q true: True bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) uimplies: supposing a ifthenelse: if then else fi  bfalse: ff exists: x:A. B[x] sq_type: SQType(T) guard: {T} bnot: ¬bb assert: b false: False not: ¬A nat_plus: + decidable: Dec(P) less_than: a < b squash: T satisfiable_int_formula: satisfiable_int_formula(fmla) top: Top le: A ≤ B
Lemmas referenced :  less_than_wf rmin_wf or_wf rless_wf real_wf imin_wf ifthenelse_wf le_int_wf bool_wf eqtt_to_assert assert_of_le_int eqff_to_assert equal_wf bool_cases_sqequal subtype_base_sq bool_subtype_base assert-bnot le_wf nat_plus_properties decidable__lt add-is-int-iff satisfiable-full-omega-tt intformand_wf intformnot_wf intformless_wf itermAdd_wf itermVar_wf itermConstant_wf intformle_wf int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_less_lemma int_term_value_add_lemma int_term_value_var_lemma int_term_value_constant_lemma int_formula_prop_le_lemma int_formula_prop_wf false_wf squash_wf true_wf add_functionality_wrt_eq imin_unfold iff_weakening_equal assert_wf bnot_wf not_wf bool_cases iff_transitivity iff_weakening_uiff assert_of_bnot
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation independent_pairFormation sqequalHypSubstitution unionElimination thin setElimination rename introduction dependent_set_memberEquality hypothesisEquality sqequalRule cut extract_by_obid isectElimination addEquality applyEquality hypothesis lambdaEquality because_Cache natural_numberEquality intEquality equalityElimination equalityTransitivity equalitySymmetry productElimination independent_isectElimination dependent_pairFormation promote_hyp dependent_functionElimination instantiate cumulativity independent_functionElimination voidElimination imageElimination pointwiseFunctionality baseApply closedConclusion baseClosed int_eqEquality isect_memberEquality voidEquality computeAll imageMemberEquality universeEquality impliesFunctionality inlFormation dependent_set_memberFormation inrFormation

Latex:
\mforall{}x,y,z:\mBbbR{}.    ((x  <  z)  \mvee{}  (y  <  z)  \mLeftarrow{}{}\mRightarrow{}  rmin(x;y)  <  z)



Date html generated: 2017_10_03-AM-08_30_28
Last ObjectModification: 2017_07_28-AM-07_26_36

Theory : reals


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