Nuprl Lemma : qle-qavg-iff-4

∀[a,b:ℚ].  uiff(a ≤ qavg(b;a);a ≤ b)


Proof




Definitions occuring in Statement :  qavg: qavg(a;b),  qle: r ≤ s,  rationals: ℚ,  uiff: uiff(P;Q),  uall: ∀[x:A]. B[x]
Definitions unfolded in proof :  rev_implies: P ⇐ Q,  rev_uimplies: rev_uimplies(P;Q),  bnot: ¬bb,  dset_of_mon: g↓set,  oset_of_ocmon: g↓oset,  set_le: ≤b,  band: p ∧b q,  set_blt: a <b b,  set_lt: a <p b,  grp_lt: a < b,  qless: r < s,  iff: P ⇐⇒ Q,  squash: ↓T,  guard: {T},  true: True,  lt_int: i <z j,  qmul: r * s,  qadd: r + s,  qsub: r - s,  qpositive: qpositive(r),  bor: p ∨bq,  q_le: q_le(r;s),  qadd_grp: <ℚ+>,  pi2: snd(t),  pi1: fst(t),  grp_le: ≤b,  infix_ap: x f y,  grp_leq: a ≤ b,  qle: r ≤ s,  prop: ℙ,  false: False,  assert: ↑b,  bfalse: ff,  eq_int: (i =z j),  btrue: tt,  ifthenelse: if b then t else f fi ,  evalall: evalall(t),  callbyvalueall: callbyvalueall,  qeq: qeq(r;s),  not: ¬A,  subtype_rel: A ⊆r B,  implies: P ⇒ Q,  uimplies: b supposing a,  and: P ∧ Q,  uiff: uiff(P;Q),  member: t ∈ T,  uall: ∀[x:A]. B[x],  qavg: qavg(a;b)
Lemmas referenced :  qmul_preserves_qle,  iff_weakening_equal,  qmul-qdiv-cancel,  subtype_rel_self,  qadd_comm_q,  equal-wf-T-base,  not_wf,  true_wf,  squash_wf,  qmul_one_qrng,  q_distrib,  qadd_inv_assoc_q,  qadd_ac_1_q,  qadd_preserves_qle,  uiff_transitivity2,  int-subtype-rationals,  qmul_wf,  qmul_preserves_qle2,  rationals_wf,  assert-qeq,  qadd_wf,  qdiv_wf,  qle_wf,  qle_witness
Rules used in proof :  universeEquality,  instantiate,  imageMemberEquality,  imageElimination,  lambdaEquality_alt,  minusEquality,  isectIsTypeImplies,  isect_memberEquality_alt,  independent_pairEquality,  sqequalBase,  baseClosed,  inhabitedIsType,  equalityIstype,  voidElimination,  productElimination,  equalitySymmetry,  equalityTransitivity,  lambdaFormation_alt,  independent_isectElimination,  because_Cache,  applyEquality,  natural_numberEquality,  universeIsType,  hypothesis,  independent_functionElimination,  hypothesisEquality,  thin,  isectElimination,  sqequalHypSubstitution,  extract_by_obid,  independent_pairFormation,  cut,  introduction,  isect_memberFormation_alt,  computationStep,  sqequalTransitivity,  sqequalReflexivity,  sqequalRule,  sqequalSubstitution

Latex:
\mforall{}[a,b:\mBbbQ{}].    uiff(a  \mleq{}  qavg(b;a);a  \mleq{}  b)



Date html generated: 2019_10_29-AM-07_45_25
Last ObjectModification: 2019_10_21-PM-07_19_18

Theory : rationals


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