Nuprl Lemma : ravg-weak-between

x,y:ℝ.  ((x ≤ y)  ((x ≤ ravg(x;y)) ∧ (ravg(x;y) ≤ y)))


Proof




Definitions occuring in Statement :  ravg: ravg(x;y) rleq: x ≤ y real: all: x:A. B[x] implies:  Q and: P ∧ Q
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q and: P ∧ Q cand: c∧ B ravg: ravg(x;y) uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a rneq: x ≠ y guard: {T} or: P ∨ Q iff: ⇐⇒ Q rev_implies:  Q prop: less_than: a < b squash: T less_than': less_than'(a;b) true: True uiff: uiff(P;Q) rev_uimplies: rev_uimplies(P;Q) rdiv: (x/y) req_int_terms: t1 ≡ t2 false: False not: ¬A top: Top
Lemmas referenced :  rmul_preserves_rleq rdiv_wf rless-int rleq_wf real_wf rmul_wf int-to-real_wf radd_wf rless_wf rmul_comm rinv_wf2 itermSubtract_wf itermMultiply_wf itermAdd_wf itermVar_wf itermConstant_wf req-iff-rsub-is-0 rleq-implies-rleq rsub_wf rleq_functionality req_transitivity radd_functionality rmul-rinv3 real_polynomial_null real_term_value_sub_lemma real_term_value_mul_lemma real_term_value_add_lemma real_term_value_var_lemma real_term_value_const_lemma
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation cut introduction extract_by_obid sqequalHypSubstitution isectElimination thin because_Cache independent_isectElimination sqequalRule hypothesis inrFormation dependent_functionElimination productElimination independent_functionElimination natural_numberEquality independent_pairFormation imageMemberEquality hypothesisEquality baseClosed approximateComputation lambdaEquality int_eqEquality intEquality isect_memberEquality voidElimination voidEquality

Latex:
\mforall{}x,y:\mBbbR{}.    ((x  \mleq{}  y)  {}\mRightarrow{}  ((x  \mleq{}  ravg(x;y))  \mwedge{}  (ravg(x;y)  \mleq{}  y)))



Date html generated: 2017_10_03-AM-08_42_01
Last ObjectModification: 2017_09_28-PM-06_00_33

Theory : reals


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