Nuprl Lemma : i-member-convex'

∀I:Interval. ∀a,b:ℝ.
  ((a ∈ I) ⇒ (b ∈ I) ⇒ (∀z:{z:ℝ| r0 < z} . ∀x,y:{z:ℝ| r0 ≤ z} .  (((x + y) = z) ⇒ (((x * a) + (y * b)/z) ∈ I))))


Proof




Definitions occuring in Statement :  i-member: r ∈ I,  interval: Interval,  rdiv: (x/y),  rleq: x ≤ y,  rless: x < y,  req: x = y,  rmul: a * b,  radd: a + b,  int-to-real: r(n),  real: ℝ,  all: ∀x:A. B[x],  implies: P ⇒ Q,  set: {x:A| B[x]} ,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  sq_stable: SqStable(P),  squash: ↓T,  prop: ℙ,  uiff: uiff(P;Q),  and: P ∧ Q,  rev_uimplies: rev_uimplies(P;Q),  rdiv: (x/y),  req_int_terms: t1 ≡ t2,  false: False,  not: ¬A,  top: Top,  iff: P ⇐⇒ Q
Lemmas referenced :  i-member-convex,  rdiv_wf,  sq_stable__rless,  int-to-real_wf,  rless_wf,  req_wf,  radd_wf,  rleq_wf,  i-member_wf,  real_wf,  interval_wf,  rmul_preserves_rleq,  rmul_wf,  itermSubtract_wf,  itermMultiply_wf,  itermConstant_wf,  itermVar_wf,  rinv_wf2,  sq_stable__rleq,  rleq_functionality,  req_transitivity,  rmul_functionality,  req_weakening,  rmul-rinv,  req-iff-rsub-is-0,  real_polynomial_null,  istype-int,  real_term_value_sub_lemma,  istype-void,  real_term_value_mul_lemma,  real_term_value_const_lemma,  real_term_value_var_lemma,  trivial-rleq-radd,  req_inversion,  rmul_preserves_req,  rsub_wf,  rminus_wf,  itermAdd_wf,  itermMinus_wf,  req_functionality,  radd_functionality,  rminus_functionality,  real_term_value_add_lemma,  real_term_value_minus_lemma,  req-implies-req,  i-member_functionality
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  independent_functionElimination,  hypothesis,  isectElimination,  setElimination,  rename,  because_Cache,  independent_isectElimination,  sqequalRule,  inrFormation_alt,  natural_numberEquality,  imageMemberEquality,  baseClosed,  imageElimination,  universeIsType,  inhabitedIsType,  setIsType,  productElimination,  approximateComputation,  lambdaEquality_alt,  int_eqEquality,  isect_memberEquality_alt,  voidElimination,  equalityTransitivity,  equalitySymmetry,  closedConclusion

Latex:
\mforall{}I:Interval.  \mforall{}a,b:\mBbbR{}.
    ((a  \mmember{}  I)
    {}\mRightarrow{}  (b  \mmember{}  I)
    {}\mRightarrow{}  (\mforall{}z:\{z:\mBbbR{}|  r0  <  z\}  .  \mforall{}x,y:\{z:\mBbbR{}|  r0  \mleq{}  z\}  .    (((x  +  y)  =  z)  {}\mRightarrow{}  (((x  *  a)  +  (y  *  b)/z)  \mmember{}  I))))



Date html generated: 2019_10_29-AM-10_46_52
Last ObjectModification: 2019_01_08-PM-06_10_39

Theory : reals


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