Nuprl Lemma : remove-repeats-length-leq

∀[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],  prop: ℙ,  le: A ≤ B,  and: P ∧ Q,  not: ¬A,  false: False,  top: Top,  less_than': less_than'(a;b),  append: as @ bs,  so_lambda: so_lambda(x,y,z.t[x; y; z]),  so_apply: x[s1;s2;s3],  squash: ↓T,  true: True,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  or: P ∨ Q,  sq_type: SQType(T),  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x]
Lemmas referenced :  int_formula_prop_wf,  int_term_value_constant_lemma,  int_term_value_add_lemma,  int_term_value_var_lemma,  int_formula_prop_le_lemma,  int_formula_prop_not_lemma,  int_formula_prop_and_lemma,  itermConstant_wf,  itermAdd_wf,  itermVar_wf,  intformle_wf,  intformnot_wf,  intformand_wf,  satisfiable-full-omega-tt,  decidable__le,  length_of_cons_lemma,  int_subtype_base,  subtype_base_sq,  remove-repeats-append-one-member,  iff_weakening_equal,  append_wf,  nil_wf,  cons_wf,  remove-repeats-append,  true_wf,  squash_wf,  list_ind_nil_lemma,  list_ind_cons_lemma,  false_wf,  length_of_nil_lemma,  remove_repeats_nil_lemma,  deq_wf,  less_than'_wf,  list_wf,  remove-repeats_wf,  length_wf,  le_wf,  list_induction
Rules used in proof :  cut,  thin,  lemma_by_obid,  sqequalHypSubstitution,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isectElimination,  hypothesisEquality,  sqequalRule,  lambdaEquality,  hypothesis,  independent_functionElimination,  lambdaFormation,  rename,  because_Cache,  dependent_functionElimination,  universeEquality,  isect_memberFormation,  introduction,  productElimination,  independent_pairEquality,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  isect_memberEquality,  voidElimination,  voidEquality,  independent_pairFormation,  natural_numberEquality,  applyEquality,  imageElimination,  intEquality,  imageMemberEquality,  baseClosed,  independent_isectElimination,  unionElimination,  instantiate,  cumulativity,  addEquality,  dependent_pairFormation,  int_eqEquality,  computeAll

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_29_16
Last ObjectModification: 2016_01_14-PM-11_21_21

Theory : decidable!equality


Home Index