Nuprl Lemma : int-rdiv-is-positive

∀x:ℝ. ∀k:ℤ-o.  (r0 < (x)/k ⇐⇒ ((r0 < x) ∧ 0 < k) ∨ ((x < r0) ∧ k < 0))


Proof




Definitions occuring in Statement :  rless: x < y,  int-rdiv: (a)/k1,  int-to-real: r(n),  real: ℝ,  int_nzero: ℤ-o,  less_than: a < b,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  or: P ∨ Q,  and: P ∧ Q,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  prop: ℙ,  rev_implies: P ⇐ Q,  or: P ∨ Q,  int_nzero: ℤ-o,  uimplies: b supposing a,  not: ¬A,  rless: x < y,  sq_exists: ∃x:A [B[x]],  false: False,  nat_plus: ℕ+,  nequal: a ≠ b ∈ T ,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  top: Top,  subtype_rel: A ⊆r B,  so_lambda: λ2x.t[x],  so_apply: x[s]
Lemmas referenced :  rless_wf,  int-to-real_wf,  int-rdiv_wf,  istype-less_than,  int_nzero_wf,  real_wf,  rdiv_wf,  rneq-int,  nat_plus_properties,  int_nzero_properties,  full-omega-unsat,  intformand_wf,  intformeq_wf,  itermVar_wf,  itermConstant_wf,  intformnot_wf,  istype-int,  int_formula_prop_and_lemma,  istype-void,  int_formula_prop_eq_lemma,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_not_lemma,  int_formula_prop_wf,  set_subtype_base,  nequal_wf,  int_subtype_base,  rless_functionality,  req_weakening,  int-rdiv-req,  rdiv-is-positive,  rless-int
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  independent_pairFormation,  universeIsType,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  natural_numberEquality,  hypothesis,  hypothesisEquality,  sqequalRule,  unionIsType,  productIsType,  setElimination,  rename,  because_Cache,  independent_isectElimination,  dependent_functionElimination,  productElimination,  independent_functionElimination,  approximateComputation,  dependent_pairFormation_alt,  lambdaEquality_alt,  int_eqEquality,  isect_memberEquality_alt,  voidElimination,  equalityIstype,  applyEquality,  intEquality,  baseClosed,  sqequalBase,  equalitySymmetry,  unionElimination,  inlFormation_alt,  promote_hyp,  inrFormation_alt

Latex:
\mforall{}x:\mBbbR{}.  \mforall{}k:\mBbbZ{}\msupminus{}\msupzero{}.    (r0  <  (x)/k  \mLeftarrow{}{}\mRightarrow{}  ((r0  <  x)  \mwedge{}  0  <  k)  \mvee{}  ((x  <  r0)  \mwedge{}  k  <  0))



Date html generated: 2019_10_29-AM-10_05_55
Last ObjectModification: 2019_04_01-PM-11_11_32

Theory : reals


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