Nuprl Lemma : filter-for-max

[A:Type]. ∀[l:A List]. ∀[m:ℤ]. ∀[g:A ⟶ ℤ].
  (||filter(λe.(g[e] =z m);l)|| ≥ supposing ((imax-list(map(λe.g[e];l)) m ∈ ℤand 0 < ||l||)


Proof




Definitions occuring in Statement :  imax-list: imax-list(L) length: ||as|| filter: filter(P;l) map: map(f;as) list: List eq_int: (i =z j) less_than: a < b uimplies: supposing a uall: [x:A]. B[x] so_apply: x[s] ge: i ≥  lambda: λx.A[x] function: x:A ⟶ B[x] natural_number: $n int: universe: Type equal: t ∈ T
Definitions unfolded in proof :  so_apply: x[s] uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a ge: i ≥  le: A ≤ B and: P ∧ Q not: ¬A implies:  Q false: False prop: top: Top subtype_rel: A ⊆B all: x:A. B[x] sq_type: SQType(T) guard: {T} l_member: (x ∈ l) exists: x:A. B[x] cand: c∧ B squash: T nat: true: True iff: ⇐⇒ Q int_seg: {i..j-} lelt: i ≤ j < k decidable: Dec(P) or: P ∨ Q satisfiable_int_formula: satisfiable_int_formula(fmla) rev_implies:  Q uiff: uiff(P;Q) rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced :  less_than'_wf length_wf filter_wf5 eq_int_wf l_member_wf equal-wf-T-base imax-list_wf map-length int_subtype_base less_than_wf pos_length imax-list-member map_wf subtype_base_sq list_wf squash_wf true_wf map_length iff_weakening_equal equal_wf map_select lelt_wf member_filter select_wf nat_properties decidable__le satisfiable-full-omega-tt intformand_wf intformnot_wf intformle_wf itermConstant_wf itermVar_wf int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_le_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_wf select_member assert_of_eq_int eta_conv null_nil_lemma btrue_wf member-implies-null-eq-bfalse btrue_neq_bfalse
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep isect_memberFormation introduction cut sqequalHypSubstitution productElimination thin independent_pairEquality lambdaEquality dependent_functionElimination hypothesisEquality because_Cache extract_by_obid isectElimination cumulativity applyEquality functionExtensionality setElimination rename hypothesis setEquality natural_numberEquality axiomEquality equalityTransitivity equalitySymmetry independent_isectElimination isect_memberEquality voidElimination voidEquality functionEquality intEquality lambdaFormation instantiate independent_functionElimination baseClosed imageElimination imageMemberEquality universeEquality dependent_set_memberEquality independent_pairFormation unionElimination dependent_pairFormation int_eqEquality computeAll hyp_replacement applyLambdaEquality

Latex:
\mforall{}[A:Type].  \mforall{}[l:A  List].  \mforall{}[m:\mBbbZ{}].  \mforall{}[g:A  {}\mrightarrow{}  \mBbbZ{}].
    (||filter(\mlambda{}e.(g[e]  =\msubz{}  m);l)||  \mgeq{}  1  )  supposing  ((imax-list(map(\mlambda{}e.g[e];l))  =  m)  and  0  <  ||l||)



Date html generated: 2017_04_17-AM-07_50_39
Last ObjectModification: 2017_02_27-PM-04_24_30

Theory : list_1


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