Nuprl Lemma : length-eq-lists-diff-elts

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


Proof not projected




Definitions occuring in Statement :  length: ||as|| decidable: Dec(P) uall: [x:A]. B[x] ge: 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 length: ||as|| exists: x:A. B[x] and: P  Q ycomb: Y member: t  T prop: append: as @ bs iff: P  Q rev_implies: P  Q top: Top subtype: S  T ge: i  j  not: A or: P  Q le: A  B false: False so_lambda: x.t[x] label: ...$L... t decision: Decision uimplies: b supposing a uiff: uiff(P;Q) decidable: Dec(P) so_apply: x[s] rev_uimplies: rev_uimplies(P;Q) sq_type: SQType(T) guard: {T} isl: isl(x) dec2bool: dec2bool(d)
Lemmas :  nil_member l_member_wf not_wf ge_wf length_wf1 no_repeats_wf member_append no_repeats_cons decidable_wf or_functionality_wrt_iff member_singleton non_neg_length length_wf_nat top_wf l_member_decidable cons_member not_functionality_wrt_iff not_over_or exists_functionality_wrt_iff and_functionality_wrt_iff append_wf remove-first_wf isl_wf no_repeats-remove-first remove-first-member-implies length-remove-first subtype_base_sq int_subtype_base remove-first-no_repeats-member dec2bool_decidable assert_wf assert_of_bnot dec2bool_wf

\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{}  (||L1||  \mgeq{}  ||L2||  )
        {}\mRightarrow{}  (\mexists{}x:T.  ((x  \mmember{}  L2)  \mwedge{}  (\mneg{}(x  \mmember{}  L1))))
        {}\mRightarrow{}  (\mexists{}x:T.  ((x  \mmember{}  L1)  \mwedge{}  (\mneg{}(x  \mmember{}  L2)))))


Date html generated: 2011_10_20-PM-03_44_28
Last ObjectModification: 2011_08_30-PM-08_00_24

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