Nuprl Lemma : ravg-dist-when-rleq

∀[x,y:ℝ].  ((ravg(x;y) - x) = ((r1/r(2)) * (y - x))) ∧ ((y - ravg(x;y)) = ((r1/r(2)) * (y - x))) supposing x ≤ y


Proof




Definitions occuring in Statement :  ravg: ravg(x;y),  rdiv: (x/y),  rleq: x ≤ y,  rsub: x - y,  req: x = y,  rmul: a * b,  int-to-real: r(n),  real: ℝ,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  and: P ∧ Q,  natural_number: $n
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  and: P ∧ Q,  cand: A c∧ B,  all: ∀x:A. B[x],  implies: P ⇒ Q,  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  true: True,  prop: ℙ,  uiff: uiff(P;Q),  req_int_terms: t1 ≡ t2,  false: False,  not: ¬A,  top: Top
Lemmas referenced :  ravg-dist,  ravg-weak-between,  req_witness,  rsub_wf,  ravg_wf,  rmul_wf,  rdiv_wf,  int-to-real_wf,  rless-int,  rless_wf,  rleq_wf,  real_wf,  rabs_wf,  rleq-implies-rleq,  itermSubtract_wf,  itermVar_wf,  itermConstant_wf,  req-iff-rsub-is-0,  req_functionality,  rabs-of-nonneg,  rmul_functionality,  req_weakening,  real_polynomial_null,  istype-int,  real_term_value_sub_lemma,  istype-void,  real_term_value_var_lemma,  real_term_value_const_lemma,  rabs-difference-symmetry
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  productElimination,  because_Cache,  independent_functionElimination,  hypothesis,  independent_pairFormation,  sqequalRule,  independent_pairEquality,  isectElimination,  closedConclusion,  natural_numberEquality,  independent_isectElimination,  inrFormation_alt,  imageMemberEquality,  baseClosed,  universeIsType,  isect_memberEquality_alt,  isectIsTypeImplies,  inhabitedIsType,  approximateComputation,  lambdaEquality_alt,  int_eqEquality,  voidElimination

Latex:
\mforall{}[x,y:\mBbbR{}].
    ((ravg(x;y)  -  x)  =  ((r1/r(2))  *  (y  -  x)))  \mwedge{}  ((y  -  ravg(x;y))  =  ((r1/r(2))  *  (y  -  x))) 
    supposing  x  \mleq{}  y



Date html generated: 2019_10_29-AM-10_03_39
Last ObjectModification: 2019_01_11-AM-11_10_53

Theory : reals


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