Nuprl Lemma : ravg-weak-between

∀x,y:ℝ.  ((x ≤ y) ⇒ ((x ≤ ravg(x;y)) ∧ (ravg(x;y) ≤ y)))


Proof




Definitions occuring in Statement :  ravg: ravg(x;y),  rleq: x ≤ y,  real: ℝ,  all: ∀x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  cand: A c∧ B,  ravg: ravg(x;y),  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  prop: ℙ,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  true: True,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  rdiv: (x/y),  req_int_terms: t1 ≡ t2,  false: False,  not: ¬A,  top: Top
Lemmas referenced :  rmul_preserves_rleq,  rdiv_wf,  rless-int,  rleq_wf,  real_wf,  rmul_wf,  int-to-real_wf,  radd_wf,  rless_wf,  rmul_comm,  rinv_wf2,  itermSubtract_wf,  itermMultiply_wf,  itermAdd_wf,  itermVar_wf,  itermConstant_wf,  req-iff-rsub-is-0,  rleq-implies-rleq,  rsub_wf,  rleq_functionality,  req_transitivity,  radd_functionality,  rmul-rinv3,  real_polynomial_null,  real_term_value_sub_lemma,  real_term_value_mul_lemma,  real_term_value_add_lemma,  real_term_value_var_lemma,  real_term_value_const_lemma
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  because_Cache,  independent_isectElimination,  sqequalRule,  hypothesis,  inrFormation,  dependent_functionElimination,  productElimination,  independent_functionElimination,  natural_numberEquality,  independent_pairFormation,  imageMemberEquality,  hypothesisEquality,  baseClosed,  approximateComputation,  lambdaEquality,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality

Latex:
\mforall{}x,y:\mBbbR{}.    ((x  \mleq{}  y)  {}\mRightarrow{}  ((x  \mleq{}  ravg(x;y))  \mwedge{}  (ravg(x;y)  \mleq{}  y)))



Date html generated: 2017_10_03-AM-08_42_01
Last ObjectModification: 2017_09_28-PM-06_00_33

Theory : reals


Home Index