Nuprl Lemma : face-of-half-cube

k:ℕ. ∀a,b,c:ℚCube(k).  (b ≤  (↑is-half-cube(k;a;b))  (∃!d:ℚCube(k). ((↑is-half-cube(k;d;c)) ∧ a ≤ d)))


Proof




Definitions occuring in Statement :  is-half-cube: is-half-cube(k;h;c) rat-cube-face: c ≤ d rational-cube: Cube(k) nat: assert: b exists!: !x:T. P[x] all: x:A. B[x] implies:  Q and: P ∧ Q
Definitions unfolded in proof :  less_than: a < b le: A ≤ B lelt: i ≤ j < k int_seg: {i..j-} rev_uimplies: rev_uimplies(P;Q) label: ...$L... t ifthenelse: if then else fi  band: p ∧b q bfalse: ff sq_type: SQType(T) rev_implies:  Q iff: ⇐⇒ Q guard: {T} subtype_rel: A ⊆B true: True squash: T is-half-interval: is-half-interval(I;J) cand: c∧ B exists: x:A. B[x] exists!: !x:T. P[x] pi1: fst(t) pi2: snd(t) top: Top so_apply: x[s] so_lambda: λ2x.t[x] or: P ∨ Q rat-point-interval: [a] rat-interval-face: I ≤ J rational-interval: Interval nat: rational-cube: Cube(k) prop: rat-cube-face: c ≤ d uimplies: supposing a and: P ∧ Q uiff: uiff(P;Q) member: t ∈ T uall: [x:A]. B[x] implies:  Q all: x:A. B[x]
Lemmas referenced :  qavg-eq-iff-2 qavg-eq-iff-7 qavg-eq-iff-3 rat-interval-face-self qavg-eq-iff-4 qavg-same qavg-eq-iff-1 istype-universe assert_functionality_wrt_uiff assert_of_band assert_of_bor iff_weakening_uiff iff_transitivity equal_wf member_wf bfalse_wf assert-qeq btrue_wf band_wf eqtt_to_assert bool_subtype_base bool_wf subtype_base_sq bool_cases qeq_wf2 bor_wf rat-point-interval_wf iff_weakening_equal subtype_rel_self rational-interval_wf true_wf squash_wf qavg_wf half-point-interval assert_wf istype-void pi1_wf_top rationals_wf pi2_wf int_seg_wf rat-interval-face_wf is-half-interval_wf istype-nat rational-cube_wf rat-cube-face_wf is-half-cube_wf istype-assert assert-is-half-cube
Rules used in proof :  functionExtensionality inrFormation_alt productEquality unionEquality cumulativity functionIsType productIsType unionIsType inlFormation_alt universeEquality instantiate baseClosed imageMemberEquality imageElimination independent_pairFormation dependent_pairFormation_alt because_Cache hyp_replacement promote_hyp voidElimination isect_memberEquality_alt independent_pairEquality lambdaEquality_alt applyLambdaEquality unionElimination rename setElimination natural_numberEquality independent_functionElimination equalitySymmetry equalityTransitivity equalityIstype applyEquality dependent_functionElimination inhabitedIsType universeIsType sqequalRule independent_isectElimination productElimination hypothesis hypothesisEquality thin isectElimination sqequalHypSubstitution extract_by_obid introduction cut lambdaFormation_alt sqequalReflexivity computationStep sqequalTransitivity sqequalSubstitution

Latex:
\mforall{}k:\mBbbN{}.  \mforall{}a,b,c:\mBbbQ{}Cube(k).
    (b  \mleq{}  c  {}\mRightarrow{}  (\muparrow{}is-half-cube(k;a;b))  {}\mRightarrow{}  (\mexists{}!d:\mBbbQ{}Cube(k).  ((\muparrow{}is-half-cube(k;d;c))  \mwedge{}  a  \mleq{}  d)))



Date html generated: 2019_10_29-AM-07_55_22
Last ObjectModification: 2019_10_24-PM-06_04_49

Theory : rationals


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