Nuprl Lemma : rmin-nonneg

∀[x,y:ℝ].  rnonneg(rmin(x;y)) supposing rnonneg(x) ∧ rnonneg(y)


Proof




Definitions occuring in Statement :  rnonneg: rnonneg(x),  rmin: rmin(x;y),  real: ℝ,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  and: P ∧ Q
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  and: P ∧ Q,  rnonneg: rnonneg(x),  all: ∀x:A. B[x],  rmin: rmin(x;y),  squash: ↓T,  prop: ℙ,  le: A ≤ B,  real: ℝ,  true: True,  subtype_rel: A ⊆r B,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  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
Lemmas referenced :  le_wf,  squash_wf,  true_wf,  imin_unfold,  iff_weakening_equal,  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,  nat_plus_wf,  less_than'_wf,  rmin_wf,  real_wf,  rnonneg_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalHypSubstitution,  productElimination,  thin,  lambdaFormation,  hypothesis,  dependent_functionElimination,  hypothesisEquality,  sqequalRule,  applyEquality,  lambdaEquality,  imageElimination,  extract_by_obid,  isectElimination,  equalityTransitivity,  equalitySymmetry,  intEquality,  setElimination,  rename,  because_Cache,  natural_numberEquality,  imageMemberEquality,  baseClosed,  universeEquality,  independent_isectElimination,  independent_functionElimination,  unionElimination,  equalityElimination,  dependent_pairFormation,  promote_hyp,  instantiate,  cumulativity,  voidElimination,  independent_pairEquality,  minusEquality,  axiomEquality,  productEquality,  isect_memberEquality

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



Date html generated: 2017_10_03-AM-08_24_39
Last ObjectModification: 2017_07_28-AM-07_23_26

Theory : reals


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