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: y req: y rmul: b int-to-real: r(n) real: uimplies: 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: supposing a and: P ∧ Q cand: c∧ B all: x:A. B[x] implies:  Q rneq: x ≠ y guard: {T} or: P ∨ Q iff: ⇐⇒ Q rev_implies:  Q less_than: a < b squash: T less_than': less_than'(a;b) true: True prop: 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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