Nuprl Lemma : permutation-nil-iff

∀[A:Type]. ∀L:A List. (permutation(A;[];L) ⇐⇒ L = [] ∈ (A List))


Proof




Definitions occuring in Statement :  permutation: permutation(T;L1;L2),  nil: [],  list: T List,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  member: t ∈ T,  prop: ℙ,  rev_implies: P ⇐ Q,  uimplies: b supposing a,  or: P ∨ Q,  cons: [a / b],  top: Top,  ge: i ≥ j ,  le: A ≤ B,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  not: ¬A
Lemmas referenced :  permutation_wf,  nil_wf,  equal-wf-T-base,  list_wf,  permutation-length,  list-cases,  product_subtype_list,  length_of_nil_lemma,  length_of_cons_lemma,  non_neg_length,  satisfiable-full-omega-tt,  intformand_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  intformeq_wf,  itermAdd_wf,  int_formula_prop_and_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_eq_lemma,  int_term_value_add_lemma,  int_formula_prop_wf,  permutation-nil
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  independent_pairFormation,  cut,  hypothesis,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  cumulativity,  hypothesisEquality,  baseClosed,  universeEquality,  independent_isectElimination,  dependent_functionElimination,  unionElimination,  promote_hyp,  hypothesis_subsumption,  productElimination,  sqequalRule,  isect_memberEquality,  voidElimination,  voidEquality,  natural_numberEquality,  dependent_pairFormation,  lambdaEquality,  int_eqEquality,  intEquality,  computeAll,  hyp_replacement,  equalitySymmetry,  Error :applyLambdaEquality

Latex:
\mforall{}[A:Type].  \mforall{}L:A  List.  (permutation(A;[];L)  \mLeftarrow{}{}\mRightarrow{}  L  =  [])



Date html generated: 2016_10_21-AM-10_17_38
Last ObjectModification: 2016_07_12-AM-05_32_48

Theory : list_1


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