Nuprl Lemma : rsqrt-positive-iff

∀x:{x:ℝ| r0 ≤ x} . (r0 < rsqrt(x) ⇐⇒ r0 < x)


Proof




Definitions occuring in Statement :  rsqrt: rsqrt(x),  rleq: x ≤ y,  rless: x < y,  int-to-real: r(n),  real: ℝ,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  set: {x:A| B[x]} ,  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],  subtype_rel: A ⊆r B,  prop: ℙ,  rev_implies: P ⇐ Q,  uimplies: b supposing a,  nat_plus: ℕ+,  rless: x < y,  sq_exists: ∃x:A [B[x]],  decidable: Dec(P),  or: P ∨ Q,  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  top: Top,  false: False,  nat: ℕ
Lemmas referenced :  rless_wf,  int-to-real_wf,  rsqrt_wf,  rsqrt-positive,  real_wf,  rleq_wf,  rnexp-rless,  rleq_weakening_equal,  nat_plus_properties,  decidable__lt,  full-omega-unsat,  intformnot_wf,  intformless_wf,  itermConstant_wf,  istype-int,  int_formula_prop_not_lemma,  istype-void,  int_formula_prop_less_lemma,  int_term_value_constant_lemma,  int_formula_prop_wf,  istype-less_than,  rnexp_wf,  decidable__le,  intformle_wf,  int_formula_prop_le_lemma,  istype-le,  rless_functionality,  req_weakening,  rsqrt-rnexp-2,  rnexp0
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,  applyEquality,  lambdaEquality_alt,  setElimination,  rename,  inhabitedIsType,  equalityTransitivity,  equalitySymmetry,  sqequalRule,  dependent_functionElimination,  dependent_set_memberEquality_alt,  setIsType,  because_Cache,  independent_functionElimination,  independent_isectElimination,  unionElimination,  approximateComputation,  dependent_pairFormation_alt,  isect_memberEquality_alt,  voidElimination,  productElimination

Latex:
\mforall{}x:\{x:\mBbbR{}|  r0  \mleq{}  x\}  .  (r0  <  rsqrt(x)  \mLeftarrow{}{}\mRightarrow{}  r0  <  x)



Date html generated: 2019_10_30-AM-07_57_40
Last ObjectModification: 2019_03_20-PM-00_31_33

Theory : reals


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