Nuprl Lemma : square-rless-implies

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


Proof




Definitions occuring in Statement :  rleq: x ≤ y,  rless: 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],  iff: P ⇐⇒ Q,  and: P ∧ Q,  prop: ℙ,  nat: ℕ,  le: A ≤ B,  less_than': less_than'(a;b),  false: False,  not: ¬A,  itermConstant: "const",  req_int_terms: t1 ≡ t2,  top: Top,  uiff: uiff(P;Q),  uimplies: b supposing a,  or: P ∨ Q,  rev_uimplies: rev_uimplies(P;Q),  guard: {T},  rge: x ≥ y
Lemmas referenced :  radd-preserves-rless,  rnexp_wf,  rminus_wf,  rless_wf,  false_wf,  le_wf,  rleq_wf,  int-to-real_wf,  real_wf,  radd_wf,  rmul_wf,  rsub_wf,  real_term_polynomial,  itermSubtract_wf,  itermAdd_wf,  itermMinus_wf,  itermMultiply_wf,  itermVar_wf,  real_term_value_const_lemma,  real_term_value_sub_lemma,  real_term_value_add_lemma,  real_term_value_minus_lemma,  real_term_value_mul_lemma,  real_term_value_var_lemma,  req-iff-rsub-is-0,  rmul-is-positive,  rless-implies-rless,  itermConstant_wf,  rless_functionality,  req_transitivity,  radd_functionality,  req_weakening,  req_functionality,  rnexp2,  rminus_functionality,  rless_transitivity1,  rless_functionality_wrt_implies,  radd_functionality_wrt_rleq,  rleq_weakening_equal
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  isectElimination,  because_Cache,  hypothesis,  productElimination,  independent_functionElimination,  dependent_set_memberEquality,  natural_numberEquality,  sqequalRule,  independent_pairFormation,  hypothesisEquality,  computeAll,  lambdaEquality,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  independent_isectElimination,  unionElimination,  equalityTransitivity,  equalitySymmetry

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



Date html generated: 2017_10_03-AM-08_49_51
Last ObjectModification: 2017_07_28-AM-07_33_55

Theory : reals


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