Nuprl Lemma : length-remove-repeats-le

∀[T:Type]. ∀[eq:EqDecider(T)]. ∀[L:T List].  (||remove-repeats(eq;L)|| ≤ ||L||)


Proof




Definitions occuring in Statement :  remove-repeats: remove-repeats(eq;L),  length: ||as||,  list: T List,  deq: EqDecider(T),  uall: ∀[x:A]. B[x],  le: A ≤ B,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  so_lambda: λ2x.t[x],  so_apply: x[s],  implies: P ⇒ Q,  all: ∀x:A. B[x],  top: Top,  le: A ≤ B,  and: P ∧ Q,  less_than': less_than'(a;b),  false: False,  not: ¬A,  prop: ℙ,  squash: ↓T,  deq: EqDecider(T),  uimplies: b supposing a,  true: True,  subtype_rel: A ⊆r B,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  ge: i ≥ j ,  decidable: Dec(P),  or: P ∨ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x]
Lemmas referenced :  less_than'_wf,  deq_wf,  int_formula_prop_wf,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_term_value_subtract_lemma,  int_term_value_add_lemma,  int_formula_prop_le_lemma,  int_formula_prop_not_lemma,  int_formula_prop_and_lemma,  itermConstant_wf,  itermVar_wf,  itermSubtract_wf,  itermAdd_wf,  intformle_wf,  intformnot_wf,  intformand_wf,  satisfiable-full-omega-tt,  decidable__le,  non_neg_length,  iff_weakening_equal,  length-filter-bnot,  subtract_wf,  l_member_wf,  bnot_wf,  filter_wf5,  add_functionality_wrt_eq,  true_wf,  squash_wf,  length_of_cons_lemma,  remove_repeats_cons_lemma,  false_wf,  length_of_nil_lemma,  remove_repeats_nil_lemma,  list_wf,  remove-repeats_wf,  length_wf,  le_wf,  list_induction
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  thin,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  sqequalRule,  lambdaEquality,  hypothesis,  independent_functionElimination,  dependent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  independent_pairFormation,  lambdaFormation,  natural_numberEquality,  rename,  applyEquality,  imageElimination,  equalityTransitivity,  equalitySymmetry,  intEquality,  setElimination,  setEquality,  because_Cache,  independent_isectElimination,  addEquality,  imageMemberEquality,  baseClosed,  universeEquality,  productElimination,  unionElimination,  dependent_pairFormation,  int_eqEquality,  computeAll,  independent_pairEquality,  axiomEquality

Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[L:T  List].    (||remove-repeats(eq;L)||  \mleq{}  ||L||)



Date html generated: 2016_05_14-PM-03_26_41
Last ObjectModification: 2016_01_14-PM-11_22_12

Theory : decidable!equality


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