Nuprl Lemma : rmax-nonneg

∀[x,y:ℝ].  rnonneg(rmax(x;y)) supposing rnonneg(x) ∨ rnonneg(y)


Proof




Definitions occuring in Statement :  rnonneg: rnonneg(x),  rmax: rmax(x;y),  real: ℝ,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  or: P ∨ Q
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  all: ∀x:A. B[x],  implies: P ⇒ Q,  rnonneg: rnonneg(x),  le: A ≤ B,  and: P ∧ Q,  not: ¬A,  false: False,  subtype_rel: A ⊆r B,  real: ℝ,  prop: ℙ,  or: P ∨ Q,  rnonneg2: rnonneg2(x),  exists: ∃x:A. B[x],  rmax: rmax(x;y),  squash: ↓T,  nat_plus: ℕ+,  true: True,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  int_upper: {i...},  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  ifthenelse: if b then t else f fi ,  bfalse: ff,  sq_type: SQType(T),  bnot: ¬bb,  assert: ↑b,  so_lambda: λ2x.t[x],  so_apply: x[s],  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  top: Top
Lemmas referenced :  less_than'_wf,  rmax_wf,  real_wf,  nat_plus_wf,  or_wf,  rnonneg_wf,  le_wf,  squash_wf,  true_wf,  imax_unfold,  iff_weakening_equal,  le_int_wf,  less_than_transitivity1,  less_than_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,  int_upper_wf,  all_wf,  rnonneg2_wf,  rnonneg-iff,  mul_preserves_le,  nat_plus_subtype_nat,  int_upper_properties,  nat_plus_properties,  decidable__le,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformle_wf,  itermMultiply_wf,  itermConstant_wf,  itermVar_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_mul_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  mul_cancel_in_le,  multiply-is-int-iff,  false_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  thin,  sqequalHypSubstitution,  dependent_functionElimination,  hypothesisEquality,  hypothesis,  independent_functionElimination,  sqequalRule,  lambdaEquality,  productElimination,  independent_pairEquality,  because_Cache,  extract_by_obid,  isectElimination,  applyEquality,  setElimination,  rename,  minusEquality,  natural_numberEquality,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  isect_memberEquality,  voidElimination,  lambdaFormation,  unionElimination,  dependent_pairFormation,  imageElimination,  intEquality,  multiplyEquality,  imageMemberEquality,  baseClosed,  universeEquality,  independent_isectElimination,  dependent_set_memberEquality,  equalityElimination,  promote_hyp,  instantiate,  cumulativity,  addLevel,  impliesFunctionality,  orFunctionality,  orLevelFunctionality,  functionEquality,  int_eqEquality,  voidEquality,  independent_pairFormation,  computeAll,  pointwiseFunctionality,  baseApply,  closedConclusion

Latex:
\mforall{}[x,y:\mBbbR{}].    rnonneg(rmax(x;y))  supposing  rnonneg(x)  \mvee{}  rnonneg(y)



Date html generated: 2017_10_03-AM-08_24_26
Last ObjectModification: 2017_07_28-AM-07_23_20

Theory : reals


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