Nuprl Lemma : qavg-between

[a,b:ℚ].  a < qavg(a;b) < supposing a < b


Proof




Definitions occuring in Statement :  qavg: qavg(a;b) q-between: a < b < c qless: r < s rationals: uimplies: supposing a uall: [x:A]. B[x]
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a qavg: qavg(a;b) q-between: a < b < c and: P ∧ Q implies:  Q prop: subtype_rel: A ⊆B qless: r < s grp_lt: a < b set_lt: a <b assert: b ifthenelse: if then else fi  set_blt: a <b b band: p ∧b q infix_ap: y set_le: b pi2: snd(t) oset_of_ocmon: g↓oset dset_of_mon: g↓set grp_le: b pi1: fst(t) qadd_grp: <ℚ+> q_le: q_le(r;s) callbyvalueall: callbyvalueall evalall: evalall(t) bor: p ∨bq qpositive: qpositive(r) qsub: s qadd: s qmul: s btrue: tt lt_int: i <j bnot: ¬bb bfalse: ff qeq: qeq(r;s) eq_int: (i =z j) true: True uiff: uiff(P;Q) cand: c∧ B rev_uimplies: rev_uimplies(P;Q) squash: T not: ¬A false: False guard: {T} iff: ⇐⇒ Q rev_implies:  Q
Lemmas referenced :  qadd_comm_q q_distrib qmul_ident qadd_preserves_qless iff_weakening_equal equal_wf assert-qeq qmul-qdiv-cancel true_wf squash_wf qadd_wf qdiv_wf qmul_wf int-subtype-rationals qmul_preserves_qless rationals_wf qless_wf qavg_wf qless_witness
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut sqequalRule sqequalHypSubstitution productElimination thin independent_pairEquality lemma_by_obid isectElimination hypothesisEquality hypothesis independent_functionElimination because_Cache isect_memberEquality equalityTransitivity equalitySymmetry natural_numberEquality applyEquality independent_isectElimination independent_pairFormation lambdaEquality imageElimination lambdaFormation voidElimination imageMemberEquality baseClosed universeEquality

Latex:
\mforall{}[a,b:\mBbbQ{}].    a  <  qavg(a;b)  <  b  supposing  a  <  b



Date html generated: 2016_05_15-PM-11_06_06
Last ObjectModification: 2016_01_16-PM-09_28_21

Theory : rationals


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