Nuprl Lemma : ravg_wf

[x,y:ℝ].  (ravg(x;y) ∈ ℝ)


Proof




Definitions occuring in Statement :  ravg: ravg(x;y) real: uall: [x:A]. B[x] member: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T ravg: ravg(x;y) uimplies: supposing a rneq: x ≠ y guard: {T} or: P ∨ Q all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q implies:  Q less_than: a < b squash: T less_than': less_than'(a;b) true: True prop:
Lemmas referenced :  real_wf rless_wf rless-int int-to-real_wf radd_wf rdiv_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut sqequalRule lemma_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis natural_numberEquality independent_isectElimination inrFormation dependent_functionElimination because_Cache productElimination independent_functionElimination independent_pairFormation imageMemberEquality baseClosed axiomEquality equalityTransitivity equalitySymmetry isect_memberEquality

Latex:
\mforall{}[x,y:\mBbbR{}].    (ravg(x;y)  \mmember{}  \mBbbR{})



Date html generated: 2016_05_18-AM-07_34_52
Last ObjectModification: 2016_01_17-AM-02_01_49

Theory : reals


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