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: 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:  Q all: x:A. B[x] prop: 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 ⊆B uimplies: supposing a guard: {T} iff: ⇐⇒ Q rev_implies:  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


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