Nuprl Lemma : rmul_reverses_rless_iff

∀x,y,z:ℝ.  ((y < r0) ⇒ (x < z ⇐⇒ (z * y) < (x * y)))


Proof




Definitions occuring in Statement :  rless: x < y,  rmul: a * b,  int-to-real: r(n),  real: ℝ,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  implies: P ⇒ Q,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  iff: P ⇐⇒ Q,  and: P ∧ Q,  member: t ∈ T,  prop: ℙ,  uall: ∀[x:A]. B[x],  rev_implies: P ⇐ Q,  uimplies: b supposing a,  rneq: x ≠ y,  or: P ∨ Q,  rdiv: (x/y),  itermConstant: "const",  req_int_terms: t1 ≡ t2,  false: False,  not: ¬A,  top: Top,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced :  rless_wf,  rmul_wf,  int-to-real_wf,  real_wf,  rmul_reverses_rless,  rdiv_wf,  rinv-negative,  rless-implies-rless,  rinv_wf2,  real_term_polynomial,  itermSubtract_wf,  itermConstant_wf,  itermVar_wf,  itermMultiply_wf,  real_term_value_const_lemma,  real_term_value_sub_lemma,  real_term_value_var_lemma,  real_term_value_mul_lemma,  req-iff-rsub-is-0,  rsub_wf,  req_wf,  req_weakening,  rless_functionality,  uiff_transitivity,  req_functionality,  req_inversion,  rmul-assoc,  rmul_functionality,  rmul_comm,  req_transitivity,  rmul-ac,  rmul-rdiv-cancel,  rmul-one-both
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  independent_pairFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  natural_numberEquality,  independent_functionElimination,  dependent_functionElimination,  lemma_by_obid,  independent_isectElimination,  inlFormation,  because_Cache,  sqequalRule,  computeAll,  lambdaEquality,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  productElimination,  promote_hyp

Latex:
\mforall{}x,y,z:\mBbbR{}.    ((y  <  r0)  {}\mRightarrow{}  (x  <  z  \mLeftarrow{}{}\mRightarrow{}  (z  *  y)  <  (x  *  y)))



Date html generated: 2017_10_03-AM-08_35_08
Last ObjectModification: 2017_07_28-AM-07_28_50

Theory : reals


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