Nuprl Lemma : longer-list-not-member

[T:Type]
  eq:x,y:T.  Dec(x = y). L1,L2:T List.
    (no_repeats(T;L1)  no_repeats(T;L2)  (||L2|| > ||L1||)  (x:T. ((x  L2)  ((x  L1)))))


Proof not projected




Definitions occuring in Statement :  length: ||as|| decidable: Dec(P) uall: [x:A]. B[x] gt: i > j all: x:A. B[x] exists: x:A. B[x] not: A implies: P  Q and: P  Q list: type List universe: Type equal: s = t no_repeats: no_repeats(T;l) l_member: (x  l)
Definitions :  uall: [x:A]. B[x] all: x:A. B[x] implies: P  Q gt: i > j length: ||as|| ycomb: Y false: False member: t  T prop: or: P  Q exists: x:A. B[x] and: P  Q cand: A c B decision: Decision top: Top subtype: S  T not: A append: as @ bs rev_implies: P  Q iff: P  Q squash: T true: True ifthenelse: if b then t else f fi  btrue: tt bfalse: ff ge: i  j  le: A  B decidable: Dec(P) uimplies: b supposing a uiff: uiff(P;Q) isl: isl(x) l_all: (xL.P[x]) l_exists: (xL. P[x]) guard: {T} bool: unit: Unit it: dec2bool: dec2bool(d)
Lemmas :  non_neg_length gt_wf length_wf1 no_repeats_wf decidable_wf l_member_decidable remove-first_wf isl_wf not_wf l_member_wf no_repeats_cons cons_member no_repeats-remove-first length-remove-first assert_wf dec2bool_wf top_wf not_functionality_wrt_iff dec2bool_decidable member_append nil_member squash_wf true_wf remove-first-cons member_singleton bool_wf bnot_wf eqtt_to_assert uiff_transitivity eqff_to_assert assert_of_bnot

\mforall{}[T:Type]
    \mforall{}eq:\mforall{}x,y:T.    Dec(x  =  y).  \mforall{}L1,L2:T  List.
        (no\_repeats(T;L1)  {}\mRightarrow{}  no\_repeats(T;L2)  {}\mRightarrow{}  (||L2||  >  ||L1||)  {}\mRightarrow{}  (\mexists{}x:T.  ((x  \mmember{}  L2)  \mwedge{}  (\mneg{}(x  \mmember{}  L1)))))


Date html generated: 2011_10_20-PM-03_44_16
Last ObjectModification: 2011_08_29-PM-06_49_05

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