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: 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] top: Top le: A ≤ B and: P ∧ Q less_than': less_than'(a;b) false: False not: ¬A prop: squash: T deq: EqDecider(T) uimplies: supposing a true: True subtype_rel: A ⊆B guard: {T} iff: ⇐⇒ Q rev_implies:  Q ge: i ≥  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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