Nuprl Lemma : rat2real-qavg

[a,b:ℚ].  (rat2real(qavg(a;b)) (rat2real(a) rat2real(b)/r(2)))


Proof




Definitions occuring in Statement :  rat2real: rat2real(q) rdiv: (x/y) req: y radd: b int-to-real: r(n) uall: [x:A]. B[x] natural_number: $n qavg: qavg(a;b) rationals:
Definitions unfolded in proof :  rev_uimplies: rev_uimplies(P;Q) uiff: uiff(P;Q) false: False sq_type: SQType(T) not: ¬A nequal: a ≠ b ∈  int_nzero: -o subtype_rel: A ⊆B prop: true: True less_than': less_than'(a;b) squash: T less_than: a < b implies:  Q rev_implies:  Q and: P ∧ Q iff: ⇐⇒ Q all: x:A. B[x] or: P ∨ Q guard: {T} rneq: x ≠ y uimplies: supposing a qavg: qavg(a;b) member: t ∈ T uall: [x:A]. B[x]
Lemmas referenced :  rat2real-qadd rdiv_functionality rat2real-qdiv req_transitivity req_functionality req_weakening nequal_wf istype-int int_subtype_base subtype_base_sq int_nzero-rational qadd_wf qdiv_wf rationals_wf rless_wf rless-int int-to-real_wf radd_wf rdiv_wf qavg_wf rat2real_wf req_witness
Rules used in proof :  sqequalBase equalityIstype voidElimination equalitySymmetry equalityTransitivity intEquality cumulativity instantiate lambdaFormation_alt dependent_set_memberEquality_alt applyEquality isectIsTypeImplies isect_memberEquality_alt inhabitedIsType universeIsType baseClosed imageMemberEquality independent_pairFormation independent_functionElimination productElimination because_Cache dependent_functionElimination inrFormation_alt sqequalRule independent_isectElimination natural_numberEquality closedConclusion hypothesis hypothesisEquality thin isectElimination sqequalHypSubstitution extract_by_obid cut introduction isect_memberFormation_alt sqequalReflexivity computationStep sqequalTransitivity sqequalSubstitution

Latex:
\mforall{}[a,b:\mBbbQ{}].    (rat2real(qavg(a;b))  =  (rat2real(a)  +  rat2real(b)/r(2)))



Date html generated: 2019_10_31-AM-05_57_28
Last ObjectModification: 2019_10_30-PM-02_56_59

Theory : reals


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