Nuprl Lemma : qavg-eq-iff-7

∀[a,b,c:ℚ].  uiff(qavg(a;b) = qavg(a;c) ∈ ℚ;b = c ∈ ℚ)


Proof




Definitions occuring in Statement :  qavg: qavg(a;b),  rationals: ℚ,  uiff: uiff(P;Q),  uall: ∀[x:A]. B[x],  equal: s = t ∈ T
Definitions unfolded in proof :  iff: P ⇐⇒ Q,  guard: {T},  prop: ℙ,  true: True,  squash: ↓T,  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),  implies: P ⇒ Q,  not: ¬A,  subtype_rel: A ⊆r B,  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 :  qadd_inv_assoc_q,  qadd_ac_1_q,  iff_weakening_equal,  subtype_rel_self,  qmul-qdiv-cancel,  istype-universe,  true_wf,  squash_wf,  equal_wf,  int-subtype-rationals,  rationals_wf,  qmul_wf,  assert-qeq,  qadd_wf,  qdiv_wf
Rules used in proof :  independent_functionElimination,  universeEquality,  instantiate,  universeIsType,  minusEquality,  isectIsTypeImplies,  axiomEquality,  isect_memberEquality_alt,  independent_pairEquality,  imageMemberEquality,  imageElimination,  lambdaEquality_alt,  rename,  setElimination,  applyLambdaEquality,  productIsType,  dependent_set_memberEquality_alt,  sqequalBase,  baseClosed,  voidElimination,  productElimination,  equalitySymmetry,  equalityTransitivity,  lambdaFormation_alt,  independent_isectElimination,  because_Cache,  applyEquality,  natural_numberEquality,  thin,  isectElimination,  sqequalHypSubstitution,  extract_by_obid,  hypothesisEquality,  inhabitedIsType,  equalityIstype,  hypothesis,  independent_pairFormation,  cut,  introduction,  isect_memberFormation_alt,  computationStep,  sqequalTransitivity,  sqequalReflexivity,  sqequalRule,  sqequalSubstitution

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



Date html generated: 2019_10_29-AM-07_45_06
Last ObjectModification: 2019_10_21-PM-09_09_37

Theory : rationals


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