Nuprl Lemma : square-rleq-implies

∀x,y:ℝ.  ((r0 ≤ y) ⇒ (x^2 ≤ y^2) ⇒ (x ≤ y))


Proof




Definitions occuring in Statement :  rleq: x ≤ y,  rnexp: x^k1,  int-to-real: r(n),  real: ℝ,  all: ∀x:A. B[x],  implies: P ⇒ Q,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  nat_plus: ℕ+,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  true: True,  and: P ∧ Q,  prop: ℙ,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  nat: ℕ,  le: A ≤ B,  false: False,  not: ¬A,  uimplies: b supposing a,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  top: Top,  guard: {T}
Lemmas referenced :  rnexp-rleq-iff,  rabs_wf,  zero-rleq-rabs,  less_than_wf,  rleq_wf,  rnexp_wf,  false_wf,  le_wf,  int-to-real_wf,  real_wf,  rnexp2-nonneg,  rleq_functionality,  req_inversion,  rabs-rnexp,  req_weakening,  rabs-of-nonneg,  rabs-as-rmax,  rleq-rmax,  rminus_wf,  rleq_transitivity
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  isectElimination,  hypothesisEquality,  hypothesis,  independent_functionElimination,  dependent_set_memberEquality,  natural_numberEquality,  sqequalRule,  independent_pairFormation,  imageMemberEquality,  baseClosed,  productElimination,  because_Cache,  independent_isectElimination,  isect_memberEquality,  voidElimination,  voidEquality

Latex:
\mforall{}x,y:\mBbbR{}.    ((r0  \mleq{}  y)  {}\mRightarrow{}  (x\^{}2  \mleq{}  y\^{}2)  {}\mRightarrow{}  (x  \mleq{}  y))



Date html generated: 2016_10_26-AM-09_08_50
Last ObjectModification: 2016_09_30-AM-10_54_12

Theory : reals


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